Death over figures belong partly to the captain and the fielders

A yorker that goes for a single and one that goes for four can be the same ball, decided by where the sweeper was standing.

Same ball. Two outcomes. One name in the column.

At the death, the distance between a good delivery and an expensive one is often ten metres of fielding placement and a boundary rider's first step. The bowler executes. The run total is then settled by a system he does not control. Field settings belong to the captain. Riders are chosen for their range. Whether a mishit lands safe is partly luck and partly whether somebody was positioned to make it not luck.

All of that lands on one bowler's figures.

The measurement question is attribution, and cricket has been poor at it because the scorecard was designed before anyone thought of the fielding side as a system. Football went the other way and now separates the chance from the finish from the goalkeeping, imperfectly but deliberately. Cricket still records runs off the bat as a property of the delivery.

You can get some distance towards a fix with what is already tracked. Where the ball pitched, where it was struck, how fast it left the bat, where it landed. From that you can build a rough expected runs figure for a shot and compare it with what happened, and the gap is fielding plus randomness. That gap is enormous at the death, larger than in any other phase, because the batter is swinging at everything and the outcomes are heavy tailed.

Heavy tails matter more than people appreciate. When most of the runs in a phase come from a handful of boundary events, the variance of any per over figure is huge. A death bowler's economy across a season rests on maybe a hundred and twenty overs, of which the extreme events number in the dozens. That is not a stable estimate. Two good seasons and one bad one is entirely consistent with no change in ability at all.

So I would stop describing anyone as a death bowling specialist on the strength of two seasons of figures. The sample is not there, and the figure is contaminated by the captain's arrangements.

What I would trust is execution rate against a stated intention, ball by ball, over several hundred deliveries. Teams collect exactly that and release none of it.

The public number is the least informative one available, and it is the one careers get discussed in.