IT has been doing coach Brenton Sanderson’s head in and frustrating supporters all year.

Why are his 5-5 Crows so good one week and so average the next?

Slow starts, bad goalkicking, too many turnovers, a lack of even contributors, too much sideways movement and injuries are among the myriad of reasons put forward by Sanderson as to the roller-coaster nature of his side.

It is certainly not mental, he says, adding “our players have a winning attitude and their belief and the way we train and prepare for games is no different as to what it was before round one’’.

AFL statistical king Champion Data has pored over the numbers and come up with cold hard facts for Adelaide’s Jekyll and Hyde characteristics.

There are major differentials between the Crows’ wins and losses in at least nine key statistical categories.

Adelaide, which in the past three weeks has been boosted by the return from long-term injury of ace goalkicker Taylor Walker, clearly doesn’t win enough of the ball when it loses.

It ranks eighth in disposals differential in defeats (-3.4) compared to second in wins (+44.6).

Critically, its contested possessions numbers are down in losses (AFL rank 15) compared to wins (rank seven) while the difference in its scores from turnovers differential is downright scary.

In victories, the Crows have a +23.4 turnover scores rating (No. 2 in the AFL).

In losses, this nosedives to a league-worst -31.4.

The efficiency in Adelaide’s forward line also lets it down when it struggles, slumping from a league-high ranking to 17th.

But Champion’s numbers point to another area of concern for Adelaide.

Damningly, when a handful of key players don’t fire, neither do the Crows.

Key forwards Josh Jenkins and James Podsiadly and midfielders Patrick Dangerfield, Scott Thompson and Matthew Wright have recorded massive differences in rankings points between wins and losses this year.

While it is natural for players to score more highly in wins, the big differentials between some of Adelaide’s prime movers is concerning.

Jenkins is averaging a whopping 38.5 SuperCoach points less in defeats than victories.

Dangerfield is averaging 29.7 points fewer, Podsiadly is at -24.8, Thompson at -24.3 and Wright at -21.2.

Dangerfield’s midfield sidekick Rory Sloane is scoring an average 18 points fewer in the team’s five losses than five wins.

However, he is still playing well in defeats, averaging a solid 102.7 points.

Playmaking defender Matthew Jaensch is another key indicator.

When he’s hot, so are the Crows.

Jaensch is averaging a healthy 100.1 SuperCoach points in wins and a modest 88.4 in losses — a -11.7 differential.

In contrast, players like ruckman Sam Jacobs (109.5 points in defeats), 2010 club champion Richard Douglas (108.4) and rebounding defender Brodie Smith (97.2) perform just as well, if not better, in losses.

“We need to get a more even contribution from our 22 players more often,’’ Sanderson noted after last Sunday’s strong win against Gold Coast.

“Through our forward line, through our midfield and through our defence, there were more winners than losers.

“We would hope to play that way every week.’’

It all starts with Jenkins, Dangerfield, Podsiadly, Thompson and Wright, it would seem.

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