A good length is not a spot on the pitch

The same delivery is a half volley to one batter and an awkward ball to another, and coaching still teaches it as a fixed target.

Junior coaching puts a cone down. Hit the cone. Six metres from the stumps, or whatever the manual says that week, and the bowler who lands it there gets told he has found a good length.

He has found a length. Whether it is good depends on the man at the other end, and that dependency is larger than most people allow for. Length is only meaningful as a description of where the ball has got to by the time it reaches the batter, and that is a function of three things the cone knows nothing about, the bowler's release height, the pace of the delivery, and the height and reach of the batter.

Take a tall batter with a long stride. A ball on that supposedly ideal length arrives at a height he can play under his eyes on the front foot, comfortably, all day. Move the same ball two feet back and he is stuck between pushing forward and rocking back, which is the only place any batter is genuinely uncomfortable. Now bowl the same two lengths at a shorter player with a compact backlift and the results invert. The second one sits up for the pull.

Release height compounds it. A bowler releasing from two and a half metres and one releasing from two metres, at the same speed, need different lengths to produce the same arrival height. This is why the tall bowler who tries to pitch it up because somebody told him to bowl fuller ends up feeding half volleys, and why the short bowler who bangs it in on a good length gets carted. Both are following the same instruction and both are wrong, because the instruction was written for a hypothetical average.

What should replace it is a per matchup target, and the tools now exist to set one. Ball tracking gives arrival height at the stumps for every delivery. Take a batter's dismissals and false shots, find the arrival height band where he struggles, and then tell each bowler in your attack the length that produces that band from his release point. It will be a different number for each of them, sometimes by a metre.

And it changes across a spell as the ball softens and the pace drops.

The cone is a teaching aid for children. Somewhere between under fifteens and a professional dressing room, somebody should take it away.