Monday, September 14, 2009

MLS Power Rankings: Crew and LA Still Headed for Showdown

By El Chupa
We've tweaked the metric and updated the rankings through last weekend's games. The Crew are still on top. Regardless of LA's embarrassing loss at home to bottom feeders DAL, they maintain their hold on second place. CHI and DC round out the top four.

One obvious oddity: DC is ranked higher than SEA. Look, DC has lost to SEA twice in the last two weeks and yet DC is ranked higher. Get over it. SEA has DC's number and obviously match up better against DC than DC matches up against them. But in terms of overall production week in and week out (wins, losses, goals, etc) DC is slightly better. We stand by the rankings in spite of the head-to-head results. Right now DC's recent form is +2 while SEA's is -2. That's a big part of the difference in the rankings.

In terms of the tweaks to the metric, we think we were weighting away wins too high and losses too low. We also took out Assists and Shots entirely, and we added a measure we call "Quality Chances" or essentially "Quality SOGs." This is a measure of the percentage of SHTS and SOGS a team creates which were actually good chances to score rather than crappy shots that had no chance at all. We've noticed that overall, the sheer number of SHTS a team generates is not a useful way of distinguishing one team from another in terms of actual goals scored. The ratio of SHTs to Gs varies hardly at all across the league. But we HAVE noticed that the best teams have a slightly higher percentage of Goals to SOGS. In other words, the best teams get more goals out of the sheer number of SOGs they create. Another way to think of it is that not all SHTs or SOGs are created equally, so the metric needs to address this. A lame-ass SOG that has absolutely no chance of going in the net ends up in the box score as a SOG and so gets weighted in the metric just as heavily as an SOG that was in fact a true quality scoring chance. The new category attempts to address this by distinguishing teams in terms of how many actual quality scoring chances they create relative to the rest of the league. We'll break the numbers down in more detail later in the week. Right now. El Chupa has to get back to work.

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