Is There Any Hope For Alexis Rios?
The good news for Alexis Rios in 2005 was improved home run production, from one homer in 426 at-bats in 2004 to 10 homers in 481 at-bats in 2005. But the boost in homer production didn't make him any more effective as a hitter. His slight increase in slugging percentage (.383 in 2004 to .397 in 2005) was off-set by a significant drop in his on-base percentage (.338 in 2004 to .306 in 2005). His strike zone judgment deteriorated, and overall he was no better last year than he was in '04. Depending on what metric you want to use, in some ways he was actually less effective. His OPS+ was virtually unchanged (83 in '04 and 84 in '05); his Runs Created per 27 outs dropped from 4.61 to 4.09.
What does the future hold for him?
On the good side of things, at age 25 with two full seasons under his belt, he still has time to develop. His athleticism and physical tools remain impressive. Scouts say he needs to make adjustments to his swing, and given his lack of progress lately there is some skepticism about whether or not these adjustments will take place. But, overall, given his tools and his age, most traditionalists would still see Rios as a valuable property and a player who should be given more time.
What about sabermetrics?
Looking at comparable players using Bill James' Sim Scores, Baseball Prospectus PECOTA system, and my own research, we find that Rios is, to this point in his career, similar to the following players.
Larry Herndon (power spike age 28)
Kevin Bass (power spike age 26)
Al Cowens (power spike age 25)
Leon Roberts (power spike age 27)
Alex Ochoa (power spike age 28)
Terry Moore (power spike age 27)
These guys were all tools players who had some initial problems, particularly with the strike zone, and less than expected power initially. All of them did eventually spike some power, at an average age of 26.8, but none of them were consistently effective offensive players, being rather erratic.
If Rios holds with this pattern, he'll have what looks like a breakthrough season in 2007 or so, but never move much beyond that, being a useful player (as all of the guys above were) but not a star, and not someone that a contending team can consistently rely on for power.