It's been 52 weeks since two Fools did battle over cheeky sportswear specialist Under Armour (NYSE:UA). Let's see how the last year has treated this popular Rule Breaker.

Bulls on parade
"Mile High Fool" Tim Beyers took the bullish side in this argument. He liked that Under Armour CEO Kevin Plank founded the company and still owned 32% of its shares outstanding. To Tim, that was a sign of committed and motivated leadership, akin to similarly founder-led market stars like Apple (NASDAQ:AAPL) and Whole Foods Market (NASDAQ:WFMI).

Other major owners at the time included gold-star mutual funds like Baron Growth and T. Rowe Price New Horizons, which also lent more muscle to the stock's market position in Tim's book. Yes, the shares were expensive at 70 times trailing earnings, but the sports apparel market is so huge that Under Armour had to have most of its growth well ahead of it.

Weak cash flows could be explained by exploding inventories, which in turn were acceptable because sales were erupting, too. Structural cash flow, a.k.a. owner earnings, was in the solid-black column, because that metric bypasses balance sheet adjustments. Nothing to worry about in the cash flow department, then.

"Click-clack. Can you hear us coming, Anders?"

Send in the bears
That's right, yours truly was poking holes in the company's armor -- and in Tim's. I pointed out that Under Armour may have invented its particular niche in performance athletic clothing, but the concept had already been copied by competitors like Adidas and Nike (NYSE:NKE). "The first-mover advantage is old-hat now," I said, "and the much bigger research and marketing resources of the competition is sure to put a serious squeeze on Under Armour's pride and joy."

Sounds a lot like fellow first-mover Crocs (NASDAQ:CROX). Doesn't it?

So UA saw the commodity bugbear coming and decided to diversify -- into some of the most contested retail spaces on the market. Who takes on Nike and Adidas in the shoe market foot-to-foot and lives to tell the tale?

Relative valuation metrics were outlandishly tall, and it's impossible to do a proper discounted cash flow calculation against negative flows. Insider ownership isn't a magic bullet, either. Too many question marks, not enough answers. "Click. Clack. Case closed."

And the winner is ...
Our readers went to the polls, and Tim pulled out a close victory -- 45% of 65 votes versus 44% for me, with 11% equally convinced by each argument. In the real world, the stock was doing fine for a while, riding as high as 37% above the Duel-date price. But the ticker crashed hard last week, and it's slightly underperformed the S&P 500 over the last year. Score one for me!

The tiebreaker goes to our CAPS community, where Under Armour is a middling three-star stock with recent forays into both two-star territory and Four-Star City. Let's just shake hands on a draw, Tim.

Delayed re-rebuttal
Unfortunately for my esteemed colleague and opponent, I get another say here. I'm still not convinced by Under Armour, for many of the same reasons cited a year ago.

Mr. Plank has sold a big chunk of his holdings, and the swarm of competing products hasn't gone away. Year-to-date free cash flow is a negative $48.7 million now, as opposed to negative $16.2 million last year. This company may have better long-term prospects than the even more commoditized Crocs, but only marginally so. The inventory buildup has only gotten worse, with the bulk of the unsold goods being finished products on a warehouse shelf somewhere, rather than unfinished products. And no, the shoe line never got any traction -- in the latest quarterly report, it was the only product category that failed to outperform the year-ago quarter significantly.

The latest crash wasn't the last, nor do I think it was the worst. Click-clack. Clunk!

Further armor-plated Foolishness:

Under Armour is a Motley Fool Rule Breakers recommendation, and Whole Foods is a Motley Fool Stock Advisor pick. New Horizons is a Champion Funds selection. Grab a handful of free 30-day trial passes and explore all of our premium newsletter services right now.

Fool contributor Anders Bylund holds no position in any of the companies discussed here. He does look good in performancewear and a Federer bandana. You can check out Anders' holdings if you like, and Foolish disclosure will go to battle for you any day.