In 2013, Jimmy Rollins saw his power decline at a drastic rate. Rollins went from hitting 23 home runs in 2012 to only six last season. Some speculate that this drop in power is a result of the lack of lineup protection around him or perhaps a product of him trying to do too much offensively because of the rampant injuries the Philadelphia Phillies had last year. Rollins also saw his OPS (on-base plus slugging percentage) drop from .743 in 2012 to .667 in 2013, as well as his SLG (slugging percentage) from .427 to .348. However, Rollins actually had an increase in doubles hitting 33 in 2012 and then 36 in 2013.
The statistic ISO is used to show a player’s isolated power by measuring the amount of extra-base hits a player has. ISO can be found by subtracting a player’s slugging percentage by his batting average. An ISO of .145 is considered league average. Having an ISO under .100 shows very bad isolated power. With that said, in 2012, Rollins had an ISO of .177, which was very good, but in 2013, his ISO dropped to .097, which was very bad.
Rollins is 35 years old. Players at that age usually see their power numbers decrease. However, Rollins has produced after age 29, which is considered the end of a hitter’s prime. From 2009 to 2012 when Rollins was around 30 years old, he posted ISOs of .173, .131, .131 and .177, respectively. Rollins’ drop in power after 2012 might not be a product of his age, but maybe a combination of trying to accomplish too much for a team depleted by injury and being over worked.
It should be noted that Rollins participated in the World Baseball Classic before the start of the regular season in 2013 as well. I believe a return to double-digit home runs is possible, but the days of 20 or 30 home runs are far behind Jimmy Rollins.