Matos is down to #14 overall now. Expect some fluctuation, but he is producing well enough to merit serious consideration on many teams.
Aggie Eric hit it right on the head. RP really only get 1 category, so when you average their 5 category totals, they get the short end of the rankings.
It is a bit more reliable with hitters. What it is doing, is averaging offensive categories (AB's R, RBI, HR, SB, not sure if they use average as well.) and ranking the players based on their per game production in each of the categories. Matos has fallen to #14 overall since the updates. Soriano leads the hitter's list. Sheff, Beltran, Pujols, Delgado, Boone, Bonds, then Matos surprisingly high in the mix.
Matos was once a top prospect. He's contributing well in all categories, and thus places high when ranked by contributions per game. He is buried down in the overall rankings because he's only played in about 30 games.
Players that follow Matos are also valuable contributors. Javy, Nomar, Brian Roberts, Corey Patterson, A-Rod, Edmonds, P Wilson, Ichiro
Brian Roberts ranking so high also surprised me, but in part convinced me to grab him as well. I'm desperate for a spark at 2B, and steals never hurt. He's hitting for average, and the team is rolling. Grabbing Matos last night has already paid off for me. Not so much his 3-5 1-run performance today, as it was dumping Aquilino Lopez off my roster so he wasn't in there for 3 ER in 0.0 innings.
Regardless, the more info you arm yourself with, the better. I agree Yahoo's player rankings, the O-Rank is somewhat garbage. The actual rankings (Rank) based on production seem to do a good job of ranking top players, and helps in identifying 'movers'. For pitchers it is a little more ambiguous, but you can still get some good info if you filter the crap out.
* Steroid induced record