Twenty20 being a recent innovation, teams and players are still trying to come to terms with strategies and tactics necessary to win the matches. One element of this is what score is good enough? Obviously, one should try to make as large a score as possible and defend even the weakest targets, but what is a par score. To some extent, people have used 150 as the par T20 score. If you exceed that, you are well-placed. If you didn’t, well, your bowlers better perform well.

But I decided to do a little more poking around. I took all the IPL group matches so far, eliminating the ones that were affected by rain (five of them – Punjab v Delhi, Punjab v Kolkata, Mumbai v Rajasthan, Chennai v Kolkata, Chennai v Punjab) and the tied match (Kolkata v Rajasthan). So totally 50 matches. Statistically, it is not the best sample because it only consider one year’s matches in one country (South Africa). But for starters, it will do for our purposes. I will try to update it with a bigger T20 set (including last year’s IPL and international matches) at a later time and blog about any discrepancies.

OK, so take a look at this chart. This plots the score ranges (made by teams batting first) and the success %age.

As would be intuitively evident, the higher the score, the greater success percentage. The key point is that below the 160 mark, you lose more matches than you win. But then the succes rate spikes. You are twice as much likely to win a match if you are over 180 than you would be if you make between 140 and 160. That is a huge change in fortunes. (No team made a score less than 100 batting first, though Rajasthan came close. It would probably be 0% win percentage)

I also took a look at the winning and losing scores, using the “Median” to avoid the effects of outliers and here is what we get (using rounded values).

Winning Score: The median winning score is 164/6. The team would win by 19 runs. That implies that teams chasing the target usually end up around 145, but in practice, the median chase only ends up at the 135-run mark.

Losing Score: The median losing score is 145/7. The team typically loses by 6 wickets, but this usually happens with only 5 balls to spare. So there have been quite a lot of last over finishes.

There is a slight difference in the losing target and the losing chase (145 vs. 135). This suggests that faced with a tough target, some teams may have already given up the chase, thus decelerating, or perhaps, more likely, they were forced to by the loss of more wickets.

In conclusion, it looks like a par score is between 145 and 164. Splitting the difference, we get 154. Which is almost exactly the score made by Delhi against Deccan today. But with Gilchrist in the murderous mood that he was in, they probably needed a lot more than that.