Tigers team stat summary: 2007 versus 2006

I'll kick off my off-season statistical analysis of the Tigers with a comparison between the 2006 and 2007 seasons. The Tigers increased their offensive output from 5.1 runs per game in 2006 to 5.5 runs per game in 2007, a year in which offense was down around the majors. However, they went from being the best in the league at preventing runs in 2006 (4.2 runs allowed per game) to 9th best in 2007 (4.9 runs allowed per game). Since their run prevention declined more than their offense gained, it's not surprising that they dropped from 95 wins last year to 88 wins this year.

Table 1: Overall

	2006		2007
	#	Rank	#	Rank
Record	95-67	3	88-74	5
R/G	5.1	5	5.5	2
RA/G	4.2	1	4.9	9

Table 2 shows that the biggest the biggest difference in offense between the two seasons was batting average. Their batting average went from 9th best last year (.274) to 2nd best this year (.287). Their walk rate increased slightly but was still near the bottom of the league. Their isolated power also did not change much. However, the improvement in batting average brought up their OBP from 12th in the league in 2006 to 4th in 2007. Their slugging average also improved from 5th best last year to 2nd best this year.

Table 2: Offense

	2006		2007
	#	Rank	#	Rank
BA	.274	9	.287	2
BB	2.65	13	2.93	12
K	6.99	13	6.5	7
ISO	.174	4	.171	2
OBP	.329	12	.345	4
SLG	.449	5	.458	2
OPS	.777	7	.802	3

Table 3 is where we see the obvious reason for their decline in wins this year. After having the best ERA in the league in 2006 (3.84), they dropped to 9th best this year (4.57). Looking at the starter and reliever splits, we can see that starters and relievers were equally responsible for the change. In both cases, they went from one of the best in 2006 to the bottom half of the league in 2007. In both years, their Fielding Independent Pitching ERA was higher than their actual ERA indicating that the pitchers were likely helped by their fielders. However, it looks like they were given somewhat better support last year.

Table 3: Pitching

	2006		2007
	#	Rank	#	Rank
FIP	4.36	3	4.73	11
ERA	3.84	1	4.57	9
SP ERA	4.00	1	4.68	9
RP ERA	3.51	2	4.37	11

Fielding is harder to measure but Table 4 illustrates that the Tigers did not rank quite as well in 2007 as they did in 2006. They were the top team in the American League in Defensive Efficiency (% of balls in play converted into outs) in 2006. They were 3rd this year. However, their percentage was actually about the same both years (.704 in 2006 versus .705 in 2007).

Using The Hardball Times play by play systems, they ranked 1st in fielding last year and 4th this year. It's important to note that different systems were used in the two years. In 2006, they broke down fielding by looking at types of balls hit (ground ball, fly ball, pop up, line drive) . These stats are explained further in an article by Dave Studeman. This system is denoted +/- in the table.

In 2007, Revised Zone Rating (RZR) was used. Each position on the field has a zone around it and a player's RZR is the proportion of balls hit into his zone which he converts into outs. Team RZR is the proportion of balls hit into all fielding zones which are converted into outs. Balls not hit into any zone are not considered in the calculation. For a further discussion of DER, RZR and other fielding statistics, check out Fielding Stats at The Hardball Times by Dave Studeman.

The chart below also breaks +/- and RZR into infield and outfield. The table shows that their outfield defense improved dramatically in 2007 (13th best in 2006 to best in 2007). However, their infield defense did not do as well (best in 2006 to 6th best in 2007). Overall, their defense was solid both years but not quite as good in 2007.

Table 4: Fielding

	2006		2007
	DER	Rank	DER	Rank
	.704	1	.705	3
	+/-	Rank	RZR	Rank
Overall	+56	1	.829	4
Infield	+74	1	.781	6
Outfield	-18	13	.898	1

In conclusion, it's easy to see that the pitching was almost entirely responsible for their decline this year. Their pitching problems were of course health related as Kenny Rogers, Jeremy Bonderman, Joel Zumaya and Fernando Rodney all suffered significant injuries which severely limited their performance this year. Nate Robertson also did not pitch as well this year and missed some time with a tired arm. They are going to need to come back healthy and strong next year. And in case they all don't, and I'm not confident that Rogers will at his age, they'll need to get some help from a young pitcher or two.