How many runs can you successfully chase batting at the death (the last 4 overs) in T20 cricket? In theory, even without no balls and wides, 6x6x4 = 144; but in reality no one has ever achieved anything like that. So what have they achieved?

We looked at over 250 matches from WBBL between 2015 and 2020 – all the games for which ball-by-ball data is available from Cricsheet – of which 119 went down to the death.

The highest successful death chase in the data we analysed was 41, but even this was a slight outlier. In reality as the batting side, you need to be chasing 38 or less from the last 4 overs to have a realistic chance of winning the match – any more than that, and the bowling side almost always wins.

On the other side of the equation, if the batting team are chasing 30 or fewer they will almost always win. This creates a Corridor of Uncertainty between 30 and 38 where the match is “in-play”, and the result could go either way.

That Corridor of Uncertainty isn’t constant however – it narrows sharply going into the final over, giving rise to the theory mentioned by Lisa Sthalekar on commentary during recent the Australia v India series that it is actually the penultimate 19th over which is the most important for the batting side.

In practice what this means is that you can go into the second-to-last over needing as many as 19, and the result will still be in-play. If you can then get this down to 8 required off the final over, you will likely win the game; but if not, 9 is almost always a losing ask. In short: if you are the batting side, don’t leave yourself with too much to do in the final over – you might be able to score 11 off the penultimate over, but you probably won’t score 11 (or even 9) off the last!

Interestingly, wickets don’t appear to have a whole lot to do with it. In matches where teams need 9-11 off the final over, they overwhelming fail; while at asks of 6-8 they almost always succeed; yet in both cases the average wickets down is the same – 5.2 – so we are seeing similar late-middle-order batters at the crease. Is it then psychological? Every batter will tell you they “back themselves” to score 9 off the final over; but do they really believe it? Studies of penalty shoot-outs in football certainly suggest a mental element to a similar situation; but the real reasons remain a matter for speculation.