2006 Team Efficiency


Measuring team efficiency

By Tom Tippett
December 11, 2006

In the mid-to-late 1990s, I started writing an annual essay about teams whose win-loss records were out of synch with their underlying stats. In the early years, these essays were largely unknown to the baseball community because they were available only as part of our annual Season Disk. That changed in 2002 when I wrote an article on this subject for ESPN.com, and we've been publishing them on ESPN.com and/or the Diamond Mind web site ever since.

The central idea is simple. Baseball analysts have developed a variety of methods for translating (a) hits and walks and other events into runs and (b) runs into wins. One can use these methods to identify teams that scored more or fewer runs than they "should have", teams that allowed more or fewer runs than they "should have", and teams that won or lost more games than they "should have" given the runs they actually scored and allowed.

In the years since our Team Efficiency article first appeared on ESPN.com, others have picked up the ball and run with it. The folks at Baseball Prospectus created a team standings page, updated daily during the season, that shows the actual standings and the standings as they would appear if every team had "normal" relationships between events and runs and wins. Bill James is now providing information of this type for the annual Bill James Baseball Handbooks. And The Hardball Times Baseball Annual has included a chapter on this subject.

What do we mean by team efficiency?

In a nutshell, you win games by outscoring your opponents, so the connection between runs and wins is very strong, even though every season produces a few teams that win more or less than you'd expect given their run differential. To explore the relationship between runs and wins, we use the pythagorean method that was developed by Bill James.

You score runs by putting together hits, walks, steals, and other offensive events, and you prevent runs by holding the other team to a minimum of those things. In most cases, there's a direct relationship between runs and the underlying events that produce runs.

We use the term efficiency to represent the ability to turn events into runs and runs into wins. An efficient team is one that produces more wins than expected given its run margin, produces more runs than expected given its offensive events, and/or allows fewer runs than expected given the hits and walks produced by their opponents.

In the 2002 edition of this article, we showed that teams that are unusually efficient (or inefficient) have exhibited a very strong tendency to revert back to the norm the next year. That's good news for some teams and bad news for others. If you'd like to find out who falls into which category, read on.

Converting runs into wins

The Bill James pythagorean method, a well-established formula based on the idea that a team's winning percentage is tightly coupled with runs scored and runs allowed. Bill's formula is quite simple ... take the square of runs scored and divide it by the sum of the squares of runs scored and runs allowed (RF = runs for, RA = runs allowed):

                                RF ** 2

  Projected winning pct =  -----------------

                           RF ** 2 + RA ** 2

In 2006, for instance, 18 of 30 teams finished with win-loss records within three games of their projected records, and 25 of 30 teams finished within five games. From 2003 to 2005, 75 of 90 teams finished within five games of their pythagorean projection.

We had a very big exception this year. The Indians won 12 fewer games than normal for a team with a run margin of +88. On a run-margin basis, they were more like an 90-win team that should have been in the thick of the division race to the end. Since 1962, when the 162-game schedule was first used in both leagues, only five teams have been at least 12 games worse than their pythagorean projection, so the 2006 Indians have assumed a dubious place in modern baseball history.

In a reversal of their 2005 season, Oakland won 93 games despite a +44 run margin that would normally produce an 86-win season. The year before, their real win-loss record fell short of their pythagorean mark by 6 games, enough to cost them the division title that year.

The Mets, Brewers and Red Sox each won 5 more games than their run margin supported. The Rangers and Braves each fell short by 6 games, while the Rockies came up short by 5 wins.

But 44 years of baseball history tells us that large deviations are unusual and tend not to be repeated the following year. In other words, the Indians could easily see a big improvement their win-loss record in 2006 even if they don't make major changes to the roster.

Converting offensive events into runs

Just as there is a strong relationship between runs and wins, it's almost always true that the more hits and walks you produce, the more runs you'll score. Sometimes, of course, a productive team comes up short on the scoreboard because they didn't hit in the clutch, didn't run the bases well, or hit line drives right at people in key situations. But this relationship holds up most of the time.

To shed some light on this relationship, we need a way to take batting stats and turn them into a measure of overall offensive production. There are several good options here, including Runs Created (Bill James), Batting Runs (Pete Palmer), Equivalent Average (Clay Davenport), OPS (on-base average plus slugging average), and Base Runs (David Smyth).

For this exercise, we'll use the sum of total bases and walks, or TBW for short. TBW is not a perfect measure, but it does have a few things going for it. It captures the most important things a team does to produce runs -- singles, extra-base hits, and walks -- and it's easy to figure without a computer.

As with other statistics, a team's TBW total can be significantly influenced by its home park. For that reason, we focus on the difference between the TBW produced by a team's hitters and the TBW allowed by its pitchers. This effectively removes the park from the equation and helps us identify teams that outproduced their opponents.

The following table shows the offensive and defensive TBW figures for the 2006 American League, along with the difference between these two figures and each team's league rank based on those differences. It also shows runs for and against, the run differential, and the rankings based on run differential. Finally, because we're trying to trace a path from TBW to runs to wins, it lists the team's win total and league rank for the year.

      ---------- TBW ----------   ------- Runs --------   - Wins -

AL     Off    Def   Diff   Rank   Off   Def  Diff  Rank   Num Rank 

NY    3256   2807    449     1    930   767   163    1     97   1
Tor 3104 2839 265 3 809 754 55 6 87 7 Bos 3117 3026 91 9 820 825 -5 10 86 8
Bal 2850 3182 -332 12 768 899 -131 12 70 12
TB 2739 3134 -395 13 689 856 -167 13 61 14
Min 2870 2718 152 8 801 683 118 3 96 2
Det 2961 2728 233 4 822 675 147 2 95 3
Chi 3127 2925 202 5 868 794 74 5 90 5
Cle 3125 2849 276 2 870 782 88 4 78 10t
KC 2770 3319 -549 14 757 971 -214 14 62 13
Oak 2914 2897 17 10 771 727 44 8 93 4
LA 2869 2701 168 6 766 732 34 9 89 6
Tex 3028 2873 155 7 835 784 51 7 80 9
Sea 2810 2982 -172 11 756 792 -36 11 78 10t

Largely because the AL dominated the NL to such a great degree in inter-league play, it was an unusual year. Ten out of fourteen AL teams were above water in TBW differential and nine had positive run margins. Boston, Minnesota, Detroit, Chicago and Seattle dominated their inter-league series, each winning at least 14 of 18 contests against the weaker league.

The Yankees were strong across the board, leading the league in TBW differential, run margin, and wins. The bottom three teams were rotten in every way. In between, things didn't exactly go according to form.

We've already talked about the Indians, who were second in TBW differential, fourth in run margin, and tied for tenth in wins. That's not easy to do. Cleveland's TBW differential of +276 is in the top 12% of all teams in the past third of a century. Fully 90% of those teams won at least 90 games, and the 2006 Indians are only the third team in that group to lose more games than they won. The 1979 Dodgers went 79-83 with a +282 TBW differential in an aberrational year that was sandwiched between two seasons of at least 92 wins. And the 1984 Phillies finished at .500 despite a differential of +333 bases. Unlike the Dodgers, the Phils did not bounce back the next year, sliding to 76 wins in 1985.

The Blue Jays also underachieved, almost entirely on offense, scoring about 70 runs less than the Runs Created formula predicts based on their underlying stats. With the league's third-best TBW differential, they're positioned to make a postseason run in 2007 if they can overcome their offensive efficiency problems.

Minnesota's TBW differential of +152 was only 8th in the league and normally wouldn't be enough to put a team in playoff contention. But the Twins turned that into the league's third-best run margin and second-best record to grab the division title on the season's final day.

In 2005, Oakland was vastly better than Los Angeles statistically but fell seven games short in the standings. This year saw an almost complete reversal, with LA having a big lead in TBW differential, being roughly even in run margin, and finishing four games behind Oakland in the standings. Combine the two years and you've got parity across the board, so one division title each is about right, even if each team stole one from the other.

Moving on to the National League:

      ---------- TBW ----------   ------- Runs --------   - Wins -

NL     Off    Def   Diff   Rank   Off   Def  Diff  Rank   Num Rank 

NY    3021   2779    242     1    834   731   103    1     97   1
Phi 3168 3121 47 4 865 812 53 3 85 4
Atl 3066 3026 40 5 849 805 44 5 79 8
Flo 2890 2947 -57 10 758 772 -14 9 78 9
Was 2889 3087 -198 14 746 872 -126 16 71 14
SL 2913 2936 -23 7 781 762 19 6 83 5
Hou 2843 2828 15 6 735 719 16 7 82 6
Cin 2999 3057 -58 11 749 801 -52 12 80 7
Mil 2783 2918 -135 13 730 833 -103 13 75 13
Pit 2664 2995 -331 16 691 797 -106 14 67 15
Chi 2752 3053 -301 15 716 834 -118 15 66 16
SD 2886 2715 171 3 731 679 52 4 88 2t
LA 3035 2855 180 2 820 751 69 2 88 2t
Col 2969 3008 -39 8 813 812 1 8 76 10t
SF 2802 2846 -44 9 746 790 -44 11 76 10t
Ari 2897 2966 -69 12 773 788 -15 10 76 10t

Just like their AL counterparts, the Mets topped the league in TBW differential, run differential, and wins, all by a very comfortable margin, yet failed to make it to the World Series. The rest of the NL East went according to form, with strong relationships between batting events, runs, and wins.

The mediocrity of the Cardinals season is clear from these numbers. Despite being outproduced by 23 bases, St. Louis eked out a run margin of +19 and a winning record by a few games. Some have taken this as an indication that the Cardinals weren't worthy of their World Series title. I don't agree.

Their regular-season stats and record were far worse than they should have been because they lost Albert Pujols, Jim Edmonds, Scott Rolen, David Eckstein, Mark Mulder, and Jason Isringhausen to injuries for long stretches.  By the time October rolled around, four of those guys were back, so the postseason Cardinals were more like the team that we projected for the best record in the NL.  I still thought the Tigers were the better team, but it's just not fair to say the Cards were undeserving.

The Reds have been defying the odds in recent years, posting an actual record that was at least four games better than their pythagorean record in four of the past five seasons. (The exception was 2005, and the high-water mark was a +10 in 2004.) Still, their stats supported a third-place finish, and that's where they wound up after contending for the top spot almost all year.

In the West, a chasm opened between the top two teams and the rest of the pack. The Padres and Dodgers posted strong numbers across the board, while the other three teams were clustered together, all of them a little below average. Based on their TBW differentials, you'd expect the top two teams to finish in a tie and the bottom three to be within a game of each other, and that's exactly what happened.

Except for the Braves, who fell a few games short, and the Reds, who picked up a few unexpected wins, it was a case of what-you-see-is-what-you-get, with everyone in the NL posting a win-loss record that matched their underlying stats.

Looking ahead

As we've pointed out, it's unusual for teams that are especially efficient or inefficient to sustain those levels the next year. Instead, they tend to revert to the normal relationships between TBW and runs and between runs and wins. That means we can identify teams that are likely to improve or fall back even if they don't make moves that change their talent level significantly.

For that reason, the Blue Jays and Indians have some reason for optimism going into 2006. Both put up impressive underlying numbers but didn't get the payoff in runs and/or wins this past season. If their offseason moves are talent-neutral or better, both teams can be expected to contend for at least a wild card next year.

Three teams would be making a mistake if they focus too much on their actual 2006 win-loss records. Boston was more like a .500 team than an 86-win team, Minnesota was quite good but not 96-win good, and Oakland was a little fortunate to win the division.

Judging by the money they're spending this winter, Boston understands that they need to put a much better team on the field in order to contend in 2007. Oakland's front office always seems to understand what they need and find a creative way to get it. Minnesota has yet to make any major moves, but they don't need to do much to remain a contender in what has become a very tough division.

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