Former Test batsman and former Pakistan coach Javed Miandad smelled a rat when the tournament was going on.  He claimed that match-fixing was occurring: “Too many teams are losing matches from winning positions”, he said.  We crunched the numbers to reveal a string of unlikely outcomes in the 2009 IPL.  Keeping reading after the jump.

We statistically tested Miandad’s claim that “teams are losing matches from winning positions” by creating a metric called winnability to measure a team’s position during in the 2nd innings.  A winnability value of 100 is par, with both teams even.  Winnability values over 100 mean the bowling team is ahead, whereas winnability values under 100 mean the chasing team is ahead.  And because we used Duckworth-Lewis as the basis of the winnability metric to normalize team position based on its resources, the metric can be compared across matches and teams.  The best way to understand what winnability means is to look at how teams do when winnability is high (or low).  In a large sample of T20 matches, when winnability went over 125, the chasing team won only 12% of such games; similarly the bowling team won only 9% of games where winnability dipped below 75.  Basically, the farther winnability is from 100, the more unlikely it for a team to make a comeback.

In every match that the chasing team wins, the winnability goes to zero by the end of the match.  Likewise, when the team bowling second wins, winnability increases towards infinity near the end.  Around 60% of matches, have winnability over 125, or under 75 at some point in the match.  In such matches, one team has a clear upper hand — only around 10% of the time does the losing team make a comeback (9% when bowling second, and 12% when batting second).

The way to measure how often teams are “losing from winning positions” is to compare winnability values with a tournament (or other group of matches) where we assume there was no fixing — we used the World Twenty20 in 2007.  What we found was that in the IPL 2009, compared to the ICC World Twenty20 2007, more teams were winning matches from positions they shouldn’t win.  There’s only a 1.6% likelihood that such a big difference could be explained by chance alone.  Here’s a list of seven matches from the 2009 IPL where a team lost from a very strong position.  For comparison, there was just one such unusual match in the 2007 World Twenty20, the September 12th match where Zimbabwe upset Australia with a max winnability of 128.

Matches with unlikely outcomes (winnability > 125, or winnability < 75)

A winnability over 125 gives the chasing team only a slim chance of winning, historically less than 10% — but the IPL teams are defying the odds. Any of these matches alone is simply a remarkable comeback, or a statistical fluke. But having all of them together, in one short tournament, is a bit suspicious. Six of the seven matches involved either Delhi (the top team in the table, by a comfortable margin) or Kolkata (the last-placed team in the table, by an even bigger margin).  In other words, these teams had very little riding on their matches at the end of the tournament.  Delhi would go through to the semis regardless of other results, and similarly Kolkata wouldn’t make it under any circumstances.  Surely the incentive to cheat is higher if you know you won’t mess up your team’s chances of making the semis.

There’s some evidence behind Miandad’s claim that more teams than normal were losing matches from winning positions. Whether this means fixing, or something else, is not for statistics to decide. But it is a very unusual pattern …

The IPL is an ideal breeding ground for fixing and corruption. In addition to the large sums of money swirling around, there’s less focus by the authorities, and also more incentive to cheat: players don’t have the patriotic burden of playing for their country, and matches can be lost with little consequence.  It deserves a closer look.

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For more details on how Winnability is calculated, please see the following paper:  Measuring the Strength of a Team’s Position in Limited-Overs Cricket. To contact us, please email team@againstthespin.com.

One thing is clear, even without looking at the data.  Twenty20 levels the playing field — with the shorter matches, it’s easier for a Zimbabwe to surprise a team like Australia.  But, as is my wont, I ended up running the numbers to compare a team’s ODI batting performance from 2006 to 2009, with its batting performance in Twenty20 matches over the same period.

The Duckworth-Lewis system comes in handy here.  It provides a proven way to judge what the 20-over equivalent of a particular 50-over score is.  The magic number is 58.6% (see this post for more info on D-L).  That is, in a T20 innings, a team has 58.6% of the resources it has in a 50-over innings.  That means that an ODI score of 300 is roughly equivalent to a Twenty20 score around 180, which sits well with my intuition.  We can look at the equivalent Twenty20 scores for some ODI teams, and then compare to that team’s actual Twenty20 scores.

Overall, every team except India exceeds the median of the predicted T20 range — perhaps there’s something systematic about D-L underestimating the Twenty20 scores.  Maybe the ODI model doesn’t map well to the T20 format.  Or maybe Twenty20 specialists like Kieron Pollard are adapting to the format better than the ODI regulars.

Twenty20 has been a boost especially to the weaker ODI teams (England, West Indies).  Both of them comfortably surpass the Duckworth-Lewis prediction in T20s.  If you have any explanations for this, please post them in the comments.

Two possibilities I can think of:

1. Duckworth-Lewis is just underestimating the prediction.  One big thing the system doesn’t take into account is the strength of individual players.  In a 20-over match, a single innings from a Gayle or a Pietersen can take the team to a good score, whereas ODI are slightly more of a team effort.
2. Perhaps it’s just that the styles of batsmen like Pollard are suited to the wham-bam game, and can’t easily be adapted to play a 50 or 100-ball innings.  This would undermine my methodology of predicting Twenty20 scores from ODI data.

Number 5: Rajasthan Royals vs. Kolkata Knight Riders, Eden Gardens, Kolkata, 17 April 2010

We start with what could be excused as the regrettable yet fairly idiotic faux pas of an ex-rookie batsman, boldly in search for his puzzlingly elusive big break. Paras Dogra comes out to bat at number seven, at a time when the Royals could use the odd extra run, to put it mildly. Having amassed a measly 103 runs by the sixteenth over, we see glimpses of Warne stoically praying to the mercurial gods of T20 cricket to shower their blessings in the form of much-needed runs on the Royals’ threadbare board. Dogra gets off the mark with a couple of shaky singles—somewhat dismissible as the unavoidable result of the adjustment period.

Then comes the rub—Murali Karthik bowls an absolute stunner, pitched just outside the line of leg stump to turn plumly towards that mystifying middle stump. And Dogra is apparently dumbfounded by this little man’s hop skip and jump, because he misses the ball entirely, and decides instead that it’s time for this mute Tarzan to call his Jane by reverse-swinging his bat wildly in a seemingly ferocious display of strength, only to topple in a hapless mess to his left as the ball happily hits the wicket. As he scrambles to gather his skirts, an unruffled Karthik casually completes his run up, deciding to let out an indulgent smile at the very end. Let’s just say, we know who got the girl.

Youtube: http://www.youtube.com/watch?v=RffEQsXdLZA?rel=0#t=2m6s
Buck up Dogra, maybe they’ll pick you for the World Cup squad next time?

Number 4: Chennai Super Kings vs. Delhi Daredevils, Feroz Shah Kotla, Delhi, 19 March 2010

There are run outs and there are run outs. Miscommunication is an inexcusable yet fairly common vice that batsmen have fondly harbored since time immemorial, ranging from shoddy hand signals, fatally misplaced assumptions and even the odd unheard call (which, to some extent, is pardonable in the IPL, given the blaring trumpets, screaming fans and deafening Bollywood music echoing off of the pavilions). But then, there are run outs of a different variety—those elicited by an overly optimistic sprightly batsman who just must leave his crease in search for greener pastures, regardless of whether he has averted the ball from the danger zone.

Case in point: After a solid start for the Super Kings with 21 runs on the board by the end of the second over, Parthiv Patel is clearly not satisfied, decides he can wait no more and makes a dash for a run where there is none. Having faced a killer yorker delivered by Dirk Nannes, he somehow comes to the conclusion that stealing a run while the ball ambles lazily right in front of him is a revolutionary idea that he will look to patent after this match. Perhaps his excitement to etch an indelible mark in the history of cricketing gaffes rendered him strangely light-footed at the thought that he may actually be known for being more than just India’s most underdeveloped-looking opening batsman. In the end, AB De Villiers snatches the ball and terminates Patel’s short, yet fleetingly sweet innings. It’s all right Patel; at least you can run back to the dressing room uninterrupted?

Youtube: http://www.youtube.com/watch?v=7autm2QEWbo?rel=0#t=1m41s
Video Caption: “What, Hayden hasn’t failed yet?? Watch me BURN!!!”

Number 3: Match 47: Delhi Daredevil vs. Mumbai Indians, Brabourne Stadium, Mumbai, 13 April 2010

Paul Collingwood pays tribute to Patel’s breathtakingly inspiring dismissal and decides he too wants to run defiantly, against all odds, and against any bastion of reason. But he wants to elevate the plane of indisputable idiocy—with four wickets down and an asking rate of 10.1 runs per over, the Daredevils are struggling to meet their target, and Collingwood enters in response to their desperate cry for rescue. Sadly for the red-bottomed men in blue, Collingwood’s nervous tick gets the better of him. After hastily failing in his attempt to put away the ball towards the leg side, he scampers off in a fit of defiance anyway, despite a clear vision of a rapidly approaching Kieron Pollard on a mission to displace his bails. Somewhere, Collingwood joins Patel in a land unknown, where the pain of broken promises to save one’s wicket is but a dwindling memory, and where the hills are alive with the sweet sound of their scampering, unfettered feet.

Youtube: http://www.youtube.com/watch?v=km0HM9225u4#t=2m34s
Video Caption: “Run Forrest, Run!!”

Number 2: Kings XI Punjab vs. Kolkata Knight Riders, Mohali, Chandigarh, 27 March 2010

Kumar Sangakkara reveals his penchant for impulsively breaking out into dainty pirouettes on the cricket pitch in this particularly befuddling dismissal. Having finally attaining double figures in a tournament that hadn’t done much for him so far in the batting department, the Kings XI skipper has comfortably made 30 runs, when he is also regrettably overtaken by a fleeting sensation of cerebral failure. As most batsmen are wont to do in these mentally paralyzing situations, he makes the lamentable decision to go for a reverse sweep—and no surprises when his attempt falls flat (literally) and he gets stumped by the KKR keeper. But what makes this dismissal exceptionally tragic (other than the fact that he completely misses the ball despite having been on the crease for almost half the innings) is the poignancy with he rhythmically sacrifices his crucial wicket. He sets aside any manly inhibitions he may never have possessed, and lets his lumbering body gracefully rotate with the pitiful disorientation of a bloated swan. He may now be seen coaching his esteemed underlings on how to perfect this routine at a cricket pitch near you.

Youtube: http://www.youtube.com/watch?v=ArhpG_JFFLA#t=2m41s
Video Caption: All in the name of Art.

Number 1: Match 1: Kolkata Knight Riders vs. Deccan Chargers, DY Patil, Mumbai, 12 March 2010

And now, the single most mind-bogglingly dumbfounding dismissal in this year’s IPL: Rohit Sharma’s unforgettably baffling shot in the tournament’s inaugural match—a shot so utterly perplexing that it inspired the noble endeavor of this humble blog post. Sharma decides to gift Angelo Matthews his first wicket of the series by briskly swinging his bat in a most bizarre manner straight towards a fielder at mid-off. How can this shot be described? Is he playing tennis? Is he swatting a fly? Unclear. What is clear is that Sharma threw away his wicket and the Chargers’ last chance at chasing their target towards victory. And to add insult to injury, watch as Sharma takes the walk of shame back to the dressing room. Is he solemnly reflecting over a momentary lapse of consciousness, you suggest? But nay! Sharma’s defiant practice strokes scream, “Watch me swing the bat stylishly as I show the world what I actually meant to do!” Indeed, Sharma’s disastrous shot pioneered what would be the first of many catastrophically comic slip-ups that this year’s IPL had to offer. Thank you?

Youtube: http://www.youtube.com/watch?v=QdiBlDHC8nQ#t=1m25s
Video Caption: “Oh yaaaar, gully danda hi to hai na?!!”

Honorable Mention: Yuvraj Singh. Need I say more?

Fans were screaming for Pollard to come in when Nayar fell in the 12th over, as the required run rate approached two runs per ball.  But instead, a promotion for Harbhajan Singh baffled pundits and fans alike.  Mumbai continued to slip, losing Harbhajan, Tendulkar, and Tiwary in the next 3 overs.  Just five overs left, only 5 wickets in hand, and nearly 14 runs an over required — surely it’s the time to send in your most destructive batsman?  Nope, instead, we saw JP Duminy come out of the Mumbai dugout.  Kieron Pollard finally came in at No. 8, with just 3 overs left, and the game all but lost.

With some help from our friends Messers Duckworth and Lewis, we can see where exactly Mumbai slipped up.  I’ve defined a measure called “Winnability”, to measure the strength of a team’s position in the 2nd innings of a run chase.  It’s pretty simple — if the chasing team has a winnability of 100, it is at a par score, with exactly enough resources in hand to hit the target in the remaining overs.  If the winnability gets above 100, the team bowling in the second innings has the advantage.  Basically, if the game was stopped at that point, the bowling team would win by D-L.  The situation is exactly reversed with winnability below 100.  For reference, no chasing team has ever overcome a winnability of over 150 in the IPL or World Twenty20; even a winnability above 130 is quite a tough ask for the chasing team.

(Continue reading below the graph)

As you can see from the figure above, the Mumbai Indians were on the back foot from the first ball.  A slow run rate meant that the Chennai Super Kings had the advantage during the Powerplay overs.  Indeed, by the halfway point, Mumbai were facing an uphill battle, which led to desperate shots, and a desperate promotion for the Turbanator.  Wickets tumbled at a regular rate, thanks to some great fielding by Raina and Vijay.  By the end of the 16th over, winnability had crept above 150, which meant Mumbai were all but out of it.

Pollard came in at the start of the 18th over, with winnability over 190.  The game had already been decided at that point, for all practical purposes.  Even KP’s lusty blows off Doug Bollinger, 22 runs off the over in all, only brought winnability down to 167.

Here’s the bottom line: Mumbai’s slow run rate in the first ten overs put them at a serious disadvantage, and the flurry of wickets in overs 11 to 15 sealed their fate.  After that, not even the might of Kieron Pollard could save them. The match had already been lost before the big man strode to the crease.

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If Chennai beat Punjab …

Chennai will go through, along with the winner of Delhi-Deccan. Kolkata have no chance

If Chennai lose to Punjab …

Chennai are definitely out, and the winner of Delhi-Deccan is definitely through. If Deccan lose to Delhi, and Kolkata beat Mumbai badly enough the next day, Kolkata could grab the fourth slot. However, if Deccan beat Delhi, then it’s likely that both Deccan & Delhi will go through, thanks to Delhi’s strong NRR.

What each team needs to do:

Delhi:  Either win, or hope Punjab beat Chennai.

Deccan: Either win, or hope that Punjab beat Chennai and Kolkata lose to Mumbai

Chennai: Win.  End of story.

Kolkata:  Hope and pray.  Both results need to go their way today (Chennai beat Punjab, and Delhi beat Deccan by a big margin), and then they have to pull off a big win of their own against the top dogs of IPL 3, the Mumbai Indians.

These IPL posts have been getting a lot of readers from Google, so I hope you folks are enjoying the statistical slant.  If you’d like to receive future posts by email, you can subscribe below.

Delhi continue to do just enough to qualify.  Once comfortably situated in 2nd, they dropped three games on the trot, before beating Chennai to stay on track for the semifinals.  They’re an 87.5% chance to make it for an unprecedented third straight year.  Delhi don’t play again until the 18th, so they’ll know exactly what they need to do going into that game versus Deccan.  If Deccan beat Punjab tomorrow, and Chennai do the same on the 18th, Delhi will need to beat Deccan on the 18th.  If either of those teams loses to Punjab, then Delhi are through regardless of their result versus Deccan.

Tomorrow’s Game:

Another must-win game for Deccan, and more net practice for Punjab.  If Deccan lose, Delhi are almost certainly through, and Deccan are left to hope that Chennai & Rajasthan lose, and then they beat Delhi on the 18th.  But if Deccan win, they’ll have a 63% chance of advancing, and can clinch it on their own by beating Delhi.

There’s still a small chance (3.1%) a team can sneak into 4th place with just 12 points, but it’s far more likely (96.1%) that 14 points will be needed.  So Chennai & Rajasthan both have must-win last games.  Thankfully those games are against Punjab & Kolkata respectively, the bottom two teams in the table.  While 14 points will likely be necessary to end up in the top 4, that alone is not sufficient — it’s probable that multiple teams end up on 14 points, and fight it out over net run rate.  If a team wants to grab a semifinal spot without depending on that lottery, it needs 16 points.  Chennai and Rajasthan can’t get there, so their qualification is not in their hands alone — they can both win their last game and still find themselves sitting out.  Deccan however, have two games in hand, so if they win both, they’re through without worrying about net run rate.

Here’s the updated table (after the game on Thursday, April 15):

The good news is that 16 points will see Deccan through.  And not just Deccan.  The probability of the 5th place team having less than 16 points is 99.8% — in other words, rack up 16 points and you’re basically on your way to the semifinals.  Each team except Punjab can reach 16 points if they perform well enough over their last games. So each team still controls its own destiny: Win all the rest of your games, and a semifinal spot is (nearly) guaranteed.

Keep reading for a preview of how tomorrow’s games may affect the standings.

Tomorrow’s Games:

The Chennai-Kolkata game is key to both teams’ fortunes.  A win for Chennai will put them ahead of Rajasthan & Deccan in the standings, and into the all-important 4th place.  From there, they’ll have a 60% chance of going through, and Kolkata will really have their backs to the will, with a measly 6% chance of making it.  Kolkata will need a big win to jump into 4th, because Rajasthan are currently ahead on net run rate.  A win will push their qualification chances to around 40%, depending on the winner of Mumbai-Delhi.  The bottom line is that this is a must-win game for both teams … and yet only one team will walk away with the points tomorrow.

The Mumbai-Delhi game is less crucial.  Mumbai are already through, and even if Delhi lose, they’ll probably hold on to their third place spot in the table, and a 71% chance at going through.  Of course, a win would probably be enough for Delhi to advance (~95%), and would let Gambhir & Co relax for the last game or two.

Here’s the updated table (after the game on Monday, April 12):

Delhi’s loss to Punjab doesn’t change much for either team.  Punjab still have about a much of a chance of going forward as Chris Martin does of hitting a Test century — mathematically possible, but not even worth mentioning.  Delhi too are still in a strong position, though their chances dropped from 89% to 83%.  Even if they lose their third match on the trot to Mumbai on Tuesday, they’ll still have an over 70% chance of going through.  That’s what a strong early season and a healthy net run rate does for you.

Tomorrow’s Game:

The Deccan Chargers’ Monday game against the Bangalore Royal Challengers is a must-win for Deccan — their chances of making the semis drop to 1.6% with a loss.   If Bangalore win, they are almost guaranteed to go through (99.6%).

Here’s the updated table (after the completed games on Sunday, April 11):

Rajasthan, despite being level with Bangalore on points, are less assured of going through, thanks to a weak net run rate (NRR).  Meanwhile, a strong net run rate could see Chennai through if they can gain a game on Rajasthan.  The following chart shows the number of points that will be needed to qualify for the semifinals.

Teams will probably need at least 14 points to advance, so Chennai, Kolkata, and Deccan will need to finish strong by winning at least 2 of their last 3 games.  All three of these teams are facing an uphill battle for the semis, and the Chennai-Kolkata match on April 13 will be of huge importance — the loser will be all but out of the running.  Net run rate will likely be a factor, and Chennai currently have the edge here.

Just for fun, we can also use the simulations to see who might be the league topper.

Unsurprisingly, Mumbai are the favorites to finish first at the end of the round robin stage.  But even Shane Warne’s boys have an outside shot, if they win their last 3 matches, and Mumbai struggle. Delhi too have a chance to finish on top, for the second year running.

These simulations were run on April 10, after 48 matches of the IPL (and before Sunday’s Delhi-Punjab & Mumbai-Rajasthan matches).  I’ll update these simulations periodically as the IPL draws to a close.  If you enjoyed this post, subscribe to receive future posts by email — no spam, I promise.

You can find the abstract of this paper at: http://www.springerlink.com/content/g551516250368338/.