Efficient Tigers

The Tigers finished 5^th in the league with 822 runs scored in 2006. However, I often heard fans complain that the Tigers did not get the most out of their hits because they did not manufacture runs and did not get enough timely hits. Of course, this was said more often in the last 2 months of the regular season when they were losing than the first 4 months.

Should the Tigers have scored more runs from their offensive output? One way to answer this question is to look at runs created. Runs created is calculated from the number of walks, singles, doubles, triples, homeruns and other things that a team does to score runs. Bill James showed in his Baseball Abstracts many years ago that runs created is highly correlated with runs scored. This tells us that runs scored are essentially the sum of other team statistics and are not, in general accounted for by unmeasured factors. There are many runs created formulas but they all have the same basic structure:

RC= (A*B)/C

where A= number of runners on base, B=advancement of runners and C=opportunities to do A and B.

One of the first runs created formulas was developed by Bill James in 1979. It was simply:

RC= ((hits+walks)*total bases)/(ab+walks).

This version is still useful for some purposes but the formula has evolved over the years and more recent versions are more accurate in estimating runs scored. Sabermetrician Dan Agonistes gave a brief history of runs created on his blog. The formula I am using here is:

RC = (((2.4*C+A)*(3*C+B))/(9*C))-(.9*C)

where

A = H+BB+HBP-CS-GIDP
B = TB+.24*(BB-IBB+HBP)+.62*SB+.5*(SH+SF)-.03*SO

C = AB+BB+HBP+SH+SF

Table 1 lists the runs, RC, difference between runs and RC and % difference for all American League teams. Table 2 does the same for National League teams. The first thing you should notice is that all but 3 teams had RC within 5% of their actual runs scored. This means that runs created gives a good estimation of runs scored in most cases.

A closer look at table 1 shows that the Tigers had 806 runs created in 2006. This means that they scored 16 or 2% more runs than their estimated total. Thus, they got more out of their hits, walks and various other positive batting events than any other team in the league. This tells us that they had either the most efficient or luckiest offense in the league. Conversely, the 2005 Tigers scored 22 or 3% fewer runs than their estimated total. This is one of many areas where the team improved in 2006.

The National League leader was the Braves at 2.1%. The least efficient or unluckiest teams in baseball were the Blue Jays (-6.7%), Reds (-7.2%) and Padres.

Table 1: Efficiency of American League Offenses in 2006

TEAM	Runs	Runs Created	difference	% difference
Detroit	822	806	16	2.0
Oakland	771	763	8	1.1
Kansas City	757	750	7	0.9
Texas	835	828	7	0.9
Minnesota	801	802	-1	-0.1
Cleveland	870	877	-7	-0.8
NY Yankees	930	943	-13	-1.4
Chicago Sox	868	881	-13	-1.5
Seattle	756	770	-14	-1.8
LA Angels	766	788	-22	-2.8
Baltimore	768	797	-29	-3.7
Boston	820	854	-34	-4.0
Tampa Bay	689	718	-29	-4.1
Toronto	809	867	-58	-6.7

Table 2: Efficiency of American League Offenses in 2006

TEAM	Runs	Runs Created	difference	% difference
Atlanta	849	832	17	2.1
San Francisco	746	732	14	1.9
NY Mets	834	834	0	0.1
Colorado	813	813	0	0.0
Milwaukee	730	732	-2	-0.3
St. Louis	781	790	-9	-1.1
Arizona	773	783	-10	-1.2
Pittsburgh	691	704	-13	-1.9
Houston	735	751	-16	-2.2
Chicago Cubs	716	734	-18	-2.4
Philadelphia	865	887	-22	-2.5
LA Dodgers	820	842	-22	-2.6
Florida	758	782	-24	-3.1
Washington	746	776	-30	-3.9
San Diego	731	776	-45	-5.8
Cincinnati	749	807	-58	-7.2