The time and space of T20 cricket
IPL and ODI data is used in this post. Data from the IPL is from the first innings of 395 games from the first six seasons. Data used from ODIs is from 1222 ODIs featuring all Test-playing teams excluding Bangladesh and Zimbabwe. Matches involving Associate teams are excluded as well.
I've been interested in the idea of a balanced contest between bat and ball for a while now. The substantive basis of my argument that T20 is not cricket in any meaningful sense but a different sport altogether is that the balance between bat and ball in a 20-over contest, with ten wickets available to the batting side and nine fielders available to the bowling side, is radically different from that in even a 50-over contest. To some cricket fans, this seems obvious; to others, it appears foreign. It is impossible to escape the conclusion that insisting that T20 is simply the very familiar ODI form minus the boring middle overs is essential to marketing the new form successfully, since the cricketing public is too shrewd to spend good money on some unknown new sport.
Here are some clear differences in the balance between bat and ball in the 20-over game and the 50-over game. I'm using only the first innings of matches. The data from the second innings is less reliable because the game is already set by the time the second innings begins.
1. The sixth wicket falls in about 48% of IPL games. It falls in nearly 80% of ODI games. The No. 8 spot is typically occupied by the best batsman among the specialist bowlers. 20% of an ODI innings is 10 overs, the same as 50% of an IPL innings. A No. 8 batsman can expect to bat as much in an ODI game as a No. 6 batsman can in a T20 game. No part of the tail is threatened in a majority of IPL first innings.
2. A team is bowled out in fewer than one in ten IPL first innings. In ODIs a team is bowled out in about three in ten first innings.
3. Contrary to what commentators say, there is no period of consolidation in T20 cricket. It is never in the interest of a pair of batsmen to maintain the same scoring rate over two or three overs unless wickets have been lost. In T20, batsmen score quicker and quicker in each successive over, or perish in the process. Steady scoring is seen in ODI cricket even when wickets are not lost, especially in the middle overs.
Two heat charts are included in this post, one for each format. A heat chart shows the scoring rate in each over for a given number of wickets lost at the start of the over. The charts are colour-coded - red indicates slower scoring rates, while green indicates higher scoring rates. As you will see, a constant run rate progresses diagonally in the T20 chart, indicating that it depends on the loss of wickets. In the ODI chart, this tendency is weaker. This comparative point is intuitively obvious, but the chart shows that it holds true generally over a large number of ODI and T20 games.
Perhaps no pair of charts conveys the illusion that T20 is merely ODI cricket compressed like the two that follow. They show when a given wicket is likely to fall in T20 and ODI cricket in a normalised fashion. I have broken down a team innings in each form into periods of 10% each - five overs for an ODI, and two overs for a T20 game.
The fall of wickets in T20 innings
The fall of wickets in ODI innings
As an example of how to read this chart, the fourth wicket in IPL games falls in the ninth or tenth over 12% of the time. It falls in the 11th or 12th over 14% of the time, and in the 17th or 18th over 18% of the time. Note that in this chart, the horizontal access indicates when a given wicket falls, and not how many wickets have been lost at the start of an over (as in the earlier charts). The coloured portions of each chart show those points in innings when a wicket is likely to fall at a rate about the average. Let's call this the "business area" of an innings.
The symmetry is wonderful. The shape and slope of this business area is apparently the same. There are, however, some seemingly minor differences. For example, the fourth wicket is 10% more likely to fall in the first half of an ODI innings than it is in the first half of a T20 innings. Nine out of ten times, the fourth wicket in a T20 innings falls after the 10th over.
Remember, the rules in the T20 and ODI games are identical. At the most, some of them have been scaled. For example, a ten-over quota in ODIs becomes a four-over quota in T20. Now regard the difference between a No. 6 batsman coming in with fewer than 60 balls remaining in eight out of ten first innings, and a No. 6 batsman coming in with at least 120 balls remaining in five innings out of 10. With the exact same rules for dismissal and run-scoring, with the same cricket ball, boundaries of the same size, the same number of fielders and the same bats.
Ahmer Naqvi wrote a few days ago that cricket was primarily about space, time and angles. I agree. It is about these things. But these things have to be given shape to make a good game - one in which all roles are attractive. Those wonderful games of cricket I grew up playing (as I'm sure did Ahmer and all of you) involved taking time and space and buildings and sidewalks and tape and tennis balls and making up rules and playing a game. We used to play an underarm version in school, where we had to use one hand on the bat handle and another on the blade of the bat. The "pitch" was about ten yards long. One could be out if the ball was caught on the first bounce, but only if the fielder was on one knee while doing so. If the ball hit any wall on the full, one was out. If it hit a wall on the first bounce, one got six runs. We were playing, as you might have guessed, in a courtyard. Some of the rules came to be because the bowlers hated being hammered all the time. Others came to be because we broke things far too often.
For over a decade now T20 has not bothered to govern its time and space. It has lived lazily in another sport's space, by snatching away another sport's time and players. This is perhaps the reason for its commercial success. It is also the reason for its cricketing failure. It could become a good game, and perhaps even a great sport. On present evidence, it doesn't seem to want to.