Alfonso Soriano has all the makings of an exciting baseball player to watch. He's long, lean and full of mean. His lanky body is quick enough to steal bases and cover a lot of ground in the field while still having the ability to swing a massive bat with enough speed and ferocity to hit the ball a mile on a consistent basis. This is why he's been paid money hand over fist to play baseball over the past 15 years. You can't look at the guy without thinking that his natural abilities will make him a game changer on the field.
The Yankees were convinced that even a 37-year-old Alfonso Soriano was capable of all this when they reacquired him at the end of July. Surprisingly, he has worked out quite well so far. Since the acquisition he's mashed 15 home runs, put up an OPS+ of 125, powered his way to a .288 ISO, and found a way to steal seven bases along the way. Even the most optimistic Yankee fan was probably not expecting this type of production and the Yankees have needed every bit of it to stay alive in the wild card race. Soriano's creating his own legend of the liquid sword with the way he has wielded the bat during his resurrection in The Bronx.
Now for the bad news. This can't possibly last. Since donning the pinstripes again, Soriano has been striking out at the highest rate of his career, he's keeping the ball on the ground at the highest rate of his career and he's also putting the ball in play at the lowest rate of his career. This normally would indicate that a player is probably not seeing the ball well at all or making good contact. However, the key to his production so far is his astronomic home run rate. Since the trade, about 23% of fly balls hit by Soriano are leaving the park. That's about two times the rate he has maintained throughout his career. Even if you factor in that he's playing in Yankee Stadium now, as a 37-year-old player, he's due to regress to the mean in a major way and since he has relied pretty much solely on home runs to produce thus far, his overall production will also regress accordingly. But hey, at least he'll be around next year too.
All data used above were obtained from baseball reference on 9/11/2013.