During the last few days, I’ve been asked the “Is Frank Thomas done?” question several times, as Mariner fans wonder if he is the right fit to take Jose Vidro’s spot at DH. During these conversations, I’ve mentioned that the main indicator of whether a player has really fallen off The Cliff is his power level. If he has lost his ability to drive the ball, then yes, he’s probably done. Mariners fans have seen a lot of players fall of The Cliff (Bret Boone, Edgar Martinez, John Olerud, and Carl Everett to name a few), and in all of their collapses, you can see that their Isolated Slugging % and Home Run Per Fly Ball % take precipitous nosedives. If a player is actually finished as a major league hitter, those two numbers are the first place to look.
With regards to Thomas, that is part of why my conclusion is that he still has more to contribute as a major league hitter. However, the situation got me thinking – is there a major league hitter right now that is a current example of a player just falling off a cliff? I think there is. Take a look at these graphs.
The first graph shows a huge decline in power – you can see a line almost straight down from the ’06 season to now. What used to be well above average power has deteriorated to an ISO of below .100. The second chart shows that the batting average on balls in play is actually not that different than the career average. In other words, it doesn’t appear that this hitter is hitting the ball hard and just having it find a fielders glove. We can’t build much regression to the mean back into his batting average, which means that since he’s not hitting for power, if he’s also not hitting for average, he’s probably done.
Who is this guy who is currently plunging off The Cilff? Mets fans could probably already guess, but it’s Carlos Delgado. Once a powerful slugger, injuries and age have caught up with him, and he just doesn’t look to be much of a productive major league player anymore.