Ryan Crowley has put his famous clamps on a number of AFL midfielders this season, but is there a direct correlation between the player Ross Lyon chooses to send his star tagger to and a key performance indicator?

Looking back through Crowley’s opponents this season, an argument can be made that Ross Lyon identifies midfielders who present the greatest danger entering their side’s attacking 50m zone as Crowley’s target.

Carlton’s Marc Murphy was kept well in check in round 19. He had the highest retain percentage and score success rate entering 50 out of Blues’ midfielders this season.

Put more simply, the Carlton captain finds his teammates with his kicks inside 50 more than the other Blues’ on-ballers, leading to scoreboard impact.

Tagging Adelaide’s Richard Douglas surprised many in round 18, considering Rory Sloane was rated by most to be the best on-baller in aCrows’ line-up without Crowley’s round 9 tag Patrick Dangerfield.

But further study reveals Douglas to be his club’s number one player for kicks inside 50 and among the top three in score success rate for inside 50s this year.

The same can be said for Richmond’s Brett Deledio (round 17), Geelong’s Joel Selwood (round 14), Gold Coast’s Gary Ablett (round 6) and Essendon’s Brent Stanton (round 3), who was surprisingly tagged ahead of Brownlow Medallist Jobe Watson.

Crowley played on West Coast’s Chris Masten in round 16, and while the Eagle ranks second at the club for kicks inside 50, he had the best retain percentage from kicks inside 50 of their midfielders that played in the second Carlton Mid Derby.

It was a similar case with North Melbourne’s Brent Harvey, who was tagged in round 13.

The Kangaroo averages the second most kicks inside 50 per game at North this year, but his retain percentage once inside the attacking arc is a super-efficient 68 per cent – clearly the best at the Roos.

Collingwood’s Scott Pendlebury, who Crowley tagged in round 7, is second behind 2012 Brownlow Medallist and prolific ball-winner Dane Swan for kicks inside 50 at the Magpies this season.

But Pendlebury’s results entering his side’s attacking 50 far exceed Swan’s.

Brisbane’s Simon Black received the Crowley tag in round 12. While he is well down for total kicks inside 50 at the Lions in 2013, Black’s kicks inside 50 were retained by his side a staggering 75 per cent of the time, and also resulted in a score 75 per cent of the time.

Crowley’s opponent has by no means been chosen exclusively by the result of kicks inside 50.

Greater Western Sydney’s Tom Scully was well behind Callan Ward in that area, but he still copped Crowley in round 20.

Sydney’s Dan Hannebery must have been pointing Crowley in Kieran Jack’s direction in round 8, considering Jack had superior inside 50 statistics.

Despite this counter-argument, strength of numbers says Lyon rates the damage a player can do entering his side’s attacking 50 very highly.

Melbourne’s Nathan Jones has already had the Crowley tag once this season, and considering he ranks second among midfielders at the Demons for kicks inside 50 and first for retain percentage and score success from those kicks, he can expect another date with ‘the glove’ this Sunday.