2005 Team Efficiency


Measuring team efficiency

By Tom Tippett
December 12, 2005

This idea is catching on.

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 weren't published anywhere other than 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 three 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 wrote similar essays for the 2005 and 2006 Bill James Baseball Handbooks. And a recent book, The Hardball Times Baseball Annual, includes a chapter by Dan Fox on this subject.

With so many people now writing about this subject, I'm not sure it makes sense for me to continue this series of articles. I have a hard time getting excited about spending time on topics that others are already covering quite well. It's a lot more interesting to spend time on subjects that are not getting enough attention.

So I'll weigh in on the 2005 season, but this may be the last time. If other writers continue to serve the baseball community well in this area, there won't be much left for me to say, and I'll direct my time and energy elsewhere.

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'll 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, 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 2005, for instance, 14 of 30 teams finished with win-loss records within three games of their projected records, and 23 of 30 teams finished within five games. In 2003 and 2004, 26 of 30 teams finished within five games of their pythagorean projection.

We had a very big exception this year. The Diamondbacks won 13 more games than normal for a team with a run margin of -160. On a run-margin basis, they were more like an 64-win team than the squad that surprised everyone by finishing second in the NL West with 77 victories. Since 1962, when the 162-game schedule was first used in both leagues, no team had ever been more than 12 games better than their pythagorean projection, so this is a modern record.

But 43 years of baseball history tells us that such large deviations are unusual and tend not to be repeated the following year. In other words, the Diamondbacks must dramatically improve their run margin in 2006 if they are to come close to matching this year's win total. The same is true of the White Sox, who finished 7 wins to the good.

The teams that most underperformed their pythagorean records were the Mets (-7), Athletics (-6), and Mariners (-6).

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 2005 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    3165   2807   +358     2    886   789  + 97    5     95   2t

Bos   3209   2916   +293     3    910   805  +105    4     95   2t

Tor   2759   2777   - 18     9    775   705  + 70    7     80   8

Bal   2856   2881   - 25    10    729   800  - 71   12     74  10

Tam   2772   3164   -392    13    750   936  -186   13     67  13

Chi   2784   2676   +108     6    741   645  + 96    6     99   1

Cle   3043   2546   +497     1    790   642  +148    1     93   5

Min   2661   2625   + 36     8    688   662  + 26    8     83   7

Det   2782   2872   - 90    11    723   787  - 64   11     71  11

KC    2604   3186   -582    14    701   935  -234   14     56  14

LAA   2745   2684   + 61     7    761   643  +118    2     95   2t

Oak   2826   2584   +242     4    772   658  +114    3     88   6

Tex   3172   2961   +211     5    865   858  +  7    9     79   9

Sea   2621   2826   -205    12    699   751  - 52   10     69  12

The AL East went pretty much according to form. The Yankees and Red Sox ran away with the TBW lead and finished tied at the top of the division. Both teams, however, were fortunate to win 95 games, as a run differential of +100 usually produces only about 90 wins. The Sox were the more fortunate of the two. If they had allowed as many runs as they "should" have, their runs allowed total would have been higher.

Toronto was a mixed bag of efficiencies and inefficiencies. The offense produced more runs than expected, while the pitching allowed many fewer runs than expected. That level of efficiency could have produced a strong win-loss record, but they gave all of that back by falling nine games short of their pythagorean record. In the end, their TBW stats were right in synch with their 80 wins.

By now, you know the story of the AL Central. Chicago was a bit below average offensively, no matter how you look at it. The pitching was very good, but they were highly efficient, too. Three teams allowed fewer TBW, and a fourth was right with them, but the White Sox still managed to finish in a virtual tie for the league lead in fewest runs allowed. In addition, Chicago won 7 more games than their run margin would normally support thanks to a 35-19 record in one-run contests.

Cleveland was just the opposite. Their TBW differential of +497 was good enough to put them among the twenty best teams from the last 32 seasons. Think about that for a second. In more than three decades, a team has been this good statistically only about once every two seasons, and the Indians still managed to miss the playoffs. Why? Their offense was inefficient and they fell four games short of their pythagorean projection in large part because they were 22-36 in one-run games.

Cleveland outproduced Chicago by 259 TBW but outscored the Sox by only 49 runs. They allowed 130 fewer TBW, but topped Chicago by only 3 runs allowed. Even with these inefficiencies, they managed to post a run margin that was 51 better than Chicago's. Still, the Indians finished six games back.

The story in the AL West was almost identical to the one we told in 2004. Once again, Oakland had a big edge statistically, failed to turn that advantage into a better run differential, and fell short in the standings. The Angels are getting very good at this. Three times in four years, they've been among the game's most efficient teams.

Moving on to the National League:

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

NL     Off    Def   Diff   Rank   Off   Def  Diff  Rank   Num Rank 

Atl   2920   2771   +149     5    769   674  + 95    2     90   2

Phi   2985   2807   +178     2    807   726  + 81    4     88   4

NY    2775   2604   +171     3    722   648  + 74    5     83   5t

Flo   2766   2766      0     8    717   732  - 15    8     83   5t

Was   2583   2736   -153    11    639   673  - 34    9     81   8t

StL   2877   2610   +267     1    805   634  +171    1    100   1

Hou   2709   2554   +155     4    693   609  + 84    3     89   3

Mil   2833   2818   + 15     7    726   697  + 29    6     81   8t

Chi   2876   2787   + 89     6    703   714  - 11    7     79  10

Cin   3094   3248   -154    12    820   889  - 69   11     73  13

Pit   2700   2931   -231    14    680   769  - 89   13     67  15t

SD    2753   2795   - 42     9    684   726  - 42   10     82   7

Ari   2943   3119   -176    13    696   856  -160   16     77  11

SF    2592   2869   -277    15    649   745  - 96   14     75  12

LA    2689   2808   -119    10    685   755  - 70   12     71  14

Col   2783   3149   -366    16    740   862  -122   15     67  15t

St. Louis ran the table for the second straight year, ranking first in TBW differential, run differential, and wins, all by a very comfortable margin.

The most interesting division was the NL East, where the Mets were right with the division leaders in TBW differential and run margin but failed to keep pace in the standings. As I noted earlier in this article, New York had the worst pythagorean differential (-7) in the majors. What could have been a great three-team race turned out to be a fairly comfortable win for the Braves.

In the Central, Houston was a solid number two behind the Cardinals. The Cubs, preseason favorites in the eyes of many, had a TBW differential that would normally support a third-place finish, but a massive inefficiency on offense dropped them behind the Brewers. Chicago produced only one fewer TBW than did the Cardinals, yet St. Louis outscored the Cubs by 102 runs.

The NL West was full of interesting situations, but they had little impact on the pennant race in 2005. For example, Arizona was fascinating in much the same way as the Blue Jays were. At first glance, you'd be tempted to say that they were incredibly lucky, winning 77 games and finishing second despite the league's worst run margin. But it looks like the run margin was as much of an anomaly as the win-loss record.

In particular, Arizona's offense wasn't all that bad. The club was in the middle of the pack in both on-base and slugging, and its walk and homerun totals were third in the league. Their strikeout to walk ratio was fifth-best. Despite these accomplishments, Arizona scored 25 fewer runs than the league average. The Runs Created formula predicts a total of 787 runs, 91 more than they actually scored.

At the same time, the Dodgers were a little unlucky to finish fourth. Their TBW differential and run margin, while wholly unimpressive, were still good enough for a second-place finish in a very weak division. Instead, because three of their rivals posted large positive pythagorean differentials (Arizona +13, San Diego +6, San Francisco +5), they were only one rung from the basement.

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 have some reason for optimism going into 2005. Not only did the Yankees and Red Sox overachieve in 2005, neither of these perennial powerhouses has improved so far this offseason. New York still has a lot of questions in its pitching staff, and Boston's roster is still unsettled due to injury risks, trade demands, and potential free agency losses. Meanwhile, Toronto should get more innings out of Roy Halliday and has added three good players in AJ Burnett, BJ Ryan, and Lyle Overbay.

In the AL Central, it will be interesting to see whether Chicago can build on its 2005 successes or whether Cleveland's statistical edge will carry the day in 2006. Similarly, Oakland must try to find a way to convert its superior TBW differential into more wins than the Angels after falling short twice in a row.

Given that the Mets were right there with the Braves and Phillies in TBW differential and run margin in 2005, their recent additions (mainly Carlos Delgado, Billy Wagner, and Paul LoDuca) make them the early favorites to unseat the Braves for the first time in eons.

In the other NL divisions, it's hard to see anyone making a serious run at the Cardinals. Houston may not have Roger Clemens this time around -- he may retire, and because they didn't offer him arbitration, he can't be signed until May 1 -- and they have a lot of ground to make up. It'll be interesting to see whether Milwaukee's young talent will begin to emerge in a big way.

Who knows what will happen in the NL West? All five teams were under water in TBW and runs in 2005, so they've all got some serious work to do.

Wrapping Up

A lot of things will change between now and opening day. This process of looking at TBW differentials and run margins doesn't tell us how the 2006 season will unfold, but it can identify some teams that might have more or less work to this winter than you may have thought.

I think it's safe to say that the Indians, Athletics, and Mets are among the good teams most likely to add to their win totals next season, even without major roster changes. The Rangers, Cubs and Dodgers are also in line for small efficiency-related bounces.

On the flip side, it will be fascinating to see whether the Angels and White Sox can sustain their recent successes. Perhaps they were a little lucky. Or perhaps they've figured out how to maximize the impact of the things that don't show up in these measures of expected runs, things such as baserunning, timely pitching (including a strong bullpen), and the judicious use of one-run strategies.

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