As I often do when I’m trying to avoid doing real work, I’ll head over to Baseball Reference and start poking around on stat pages. I took a look at Carlos Guillen’s because of his remarkable season last year. One of the great features of BR, is the list of comparison players. I wanted to see who Guillen was similar to at this stage of his career. The list was far from encouraging with the likes of Julio Lugo, Adam Kennedy, Dickie Thon, and Neifi Perez among others.

One name that did catch my attention is Rich Aurilia. As Tiger fans remember, Detroit pursued Aurilia only to see him sign with Seattle. Of course, Guillen became expendable from Seattle’s viewpoint and the Tigers were the beneficiary.

The other thing that most remember about Aurilia is his tremendous season in 2001 in which he hit 37 homers, had an OPS+ of 148, and made the All Star team. Aurilia’s season came out of nowhere, and he hasn’t come close to approaching those numbers again. Considering that Carlos Guillen had a 2004 season that far surpassed what he had totaled to that point in his career, I thought it would be worthwhile to take a look at how the two compared.

Before Peak							
	Age	Games	BA	OBP	SLG	RC	RC/27
Guillen	22-27	488	.264	.331	.383	211	4.33
Aurilia	23-28	575	.270	.324	.419	260	4.74
							
							
Peak							
	Age	Games	BA	OBP	SLG	RC	RC/27
Guillen	28	136	.318	.379	.542	107	7.62
Aurilia	29	156	.324	.369	.572	134	8.00
							
							
Post Peak							
	Age	Games	BA	OBP	SLG	RC	RC/27
Guillen	29-??	???	???	???	???	???	???
Aurilia	30-32	386	.261	.313	.395	178	4.22

Aurilia broke in with the Giants at age 23. Guillen beat him by a year and came up at 22. Over the first 6 years of their careers, they hit for a similar batting average. Guillen was slightly better at getting on base, but Aurilia hit for more power reaching 20 homers in both 1999 and 2000.

Then came the big breakout seasons. Aurilia’s occured at age 29. His RC/27 (runs created per 27 outs, basically the number of runs a team of 9 Aurilia’s would score in a game). jumped 69% from his pre-peak seasons. His OPS jumped 27% from his career to date numbers.

Guillen’s big season (so far, hopefully there will be more) came at age 28. Like Aurilia, Guillen’s numbers for batting average, on base average, and slugging percentage all jumped tremendously. His RC/27 increased 76%, and his OPS jumped 29%.

Here’s the downer. While we don’t know what the future holds for Carlos Guillen we can look at what happened to Rich Aurilia after his big season. In the three seasons since his 2001 peak season, his numbers are actually worse than they were prior to the peak. Despite signing a brand new contract with Seattle last year, his performance was so bad, they released him midseason.

Rich Aurilia’s collapse after an All Star season doesn’t mean that the same thing will occur with Guillen. Guillen is a year younger than Aurilia was during their respective big seasons which could be a good sign. Also Guillen’s big season came after a change of scenery where Aurilia’s came in the middle of his tenure with the Giants. Guillen’s role in Seattle was never clearly defined, and when he came to Detroit he knew he’d be the starting shortstop. Also Guillen’s success wasn’t predicated on a cushy lineup spot (Aurilia was in the same lineup with Bonds and Kent who both slugged over .500). The Tigers offense was pretty good last year, but Guillen hit in all of the first 7 spots in the order.

In looking forward to next season, my guess is that Guillen won’t repeat his 2004 performance, but I also don’t see him falling off completely like Aurilia did. I’m thinking that Guillen’s power numbers will be sustained or only slip slightly because the increase in slugging came not only from home runs, but from an increase in extra base hits across the board. His average, may dip some which would drag down his on base average as well. Then again, what do I know. I thought Eric Munson was going to put it all together last year.