Take it for what it is, but Baseball Prospectus is projecting the A's as the most likely winner of the A.L. West.

They run the rest of the season 1 Million times a day and update the odds on a daily basis.

It's addictive to check it.

Current Odds:

Average wins by position in AL west:  87.2 83.6 80.6 76.6
AL West           W    L    Pct3  Avg W  Avg L  Champions  Wild Card   Playoffs
Athletics         57   51   .509   84.1   77.9   39.10082     .00877   39.10959
Angels            55   52   .542   82.8   79.2   27.62870     .00779   27.63649
Rangers           54   54   .549   82.5   79.5   26.44583     .00355   26.44939
Mariners          53   54   .491   78.6   83.4    6.82465     .00092    6.82557

In a close race, these odds change significantly with each win, so beware, it is a VERY addictive website.