Of all the surprising subplots to emerge from season 2015, the rise of the West Coast Eagles may well be the most confounding.

Ten minutes into the season, when Mitch Brown went down clutching his left knee, the Eagles had lost their two best key defenders.

If Eric Mackenzie’s season-ending injury in the NAB Cup wasn’t bad enough, Brown’s loss meant the Eagles would be undersized down back for 22 games.

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They went on to lose to the Bulldogs by 10 points, and all signs pointed toward another barren season for coach Adam Simpson.

Twelve weeks later, the Eagles are in second place with a 9-3 record and the best percentage in the league.

Jeremy McGovern has been Herculean down back for West Coast. Photo: Getty

Except for a woeful first half against Fremantle in April, they’ve looked good against everyone put before them.

As difficult as it is to conceive, the loss of Mackenzie and Brown may have actually helped them.

Both are wonderful negating defenders, but their disposal and decision-making is often haphazard.

Huge credit must go to replacements Jeremy McGovern and Will Schofield.

McGovern has taken the opposition’s best forward most weeks, and he leads the AFL for intercept marks with 41.

Schofield has put on weight to be able to compete one-on-one, but his speed off half-back still sets up many forward thrusts.

With McGovern and Schofield, plus the improvement this year from Sharrod Wellingham, Brad Sheppard and Sam Butler – marshaled by skipper Shannon Hurn – the Eagles’ back six is getting it done week after week.

In the middle, Nic Naitanui is giving plenty of footy to the likes of Matt Priddis and Luke Shuey, while Elliott Yeo’s dash and marking ablility have given a new dimension for opposition sides to ponder.

Andrew Gaff and Chris Masten still look undersized against more mature midfields, but their elite endurance results in leather poisoning most weekends.

Gaff, in particular, has been outstanding this season, launching countless attacks through the middle.

Sharrod Wellingham is enjoying his best season since moving west from Collingwood. Photo: Getty

And once inside 50 they have stars like Josh Kennedy, Mark LeCras and the returning Jack Darling – who still has a few more gears to crank – presenting migraine-strength headaches for the very best defences.

Simpson and his team of coaches, in particular Adrian Hickmott who takes charge of the defenders, must be given plenty of plaudits.

Simpson is an interesting character, a man of quiet conviction who you get the impression is still finding his sea legs in media land.

If his comments after Friday night’s win over Richmond are anything to go by, he’s keeping the lid screwed on as tightly as he can.

“The boys aren’t surprised,” he said of their incredible first half of the season.

“We just want to improve from last year to be honest. We won 11 games, that’s our goal – to get past that.

“We’re going to get exposed at some stage. We’re going to learn some valuable lessons as we go.”

Can they go all the way?

At this stage the Eagles haven’t come across Sydney or Hawthorn and were found a long way short of Fremantle’s mark.

Their fate could rest with a block of four weeks from Round 17.

They host Sydney at Domain Stadium, journey to the Gold Coast before returning home for clashes against the Hawks and Dockers.

Win three of those four and the top two could be a reality. Lose three of them and their spot in the finals comes under question.

But for what they’ve done so far, with plenty of injuries to key personnel, Simpson and the rest of the West Coast Eagles should take a mid-season bow.