Mike Freire - Expected Win Percentage, Revisited

Greetings, Mets' fans!

A few months ago, I presented a series of articles on a variety of "new" statistical models that have become "all the rage" in baseball.  Within that series, I mentioned something called the Expected Win Percentage that uses a team's "runs scored" and "runs surrendered" to calculate a probable winning percentage.  That percentage could then be used in conjunction with a team's total games played to estimate the overall win/loss record.

See below for the details (or, if you prefer, skip ahead to the following paragraph);


                                                                              (Runs Scored)2

    Expected Win Percentage   =                   ----------------------------------
                                                               (Runs Scored)2 + (Runs Allowed)2


Take a team's total runs scored (squared) and divide that number by the sum of a team's runs scored (squared) and a team's runs allowed (squared). The end result of this computation will be expressed as a percentage between 0.000 and 1.000, which will be used in the next phase of the overall exercise.

     Expected Win Total  =  (Expected Win Percentage) x (Total Number of Games Played)


I bring this calculation back from the archives because it is an interesting statistical model AND it can also be used to identify a team that may be "playing over their heads" or perhaps "lying in the weeds".  With just a few games left in the regular season, most of the probable playoff match ups are set so knowing what a team's "potential" may be is a precursor of how they may perform in the playoffs.

Consider the following;

American League

1.  Boston          103-47  (98-52)     +5

2.  Houston         94-56   (103-47)    -9

3.  Cleveland      83-66   (91-58)       -8

4.  New York       91-58   (91-58)        0

5.  Oakland         90-60   (87-63)     +3

OK, so upon first blush, it would appear that Boston has overachieved a bit (positive total), while the Astros and Indians have significantly underachieved (negative total).  The other two probably playoff teams are pretty much playing to their potential, especially the Yankees who are right on the number.

So, what does this mean?  Well, a team that has a large spread (positive or negative) usually has a corresponding record in "close" or one run ballgames.  There are times when a team is exceptionally lucky or unlucky, or it could be a measure of a team's bullpen and grasp of basic fundamentals which  usually dictate success, or lack thereof in tight contests.

With that being said, let's not get crazy here.......the Red Sox are still playing excellent baseball and they will be quite difficult to beat in a short series.  BUT, don't overlook our defending champs and I would also be leery of Cleveland who are experienced and playing good baseball as the season comes to a close (the opening series between Cleveland and Houston should be an excellent match up). 

National League

1.  Chicago          88-62   (88-62)     0

2.  Atlanta             82-67  (86-64)    -4

3.  Los Angeles   83-68  (93-58)      -10

4.  Milwaukee      86-65  (83-69)     +3

5.  St Louis          83-68   (84-67)    -1

***Colorado        82-68    (74-76)    +8

Much like the American League, the National League has a few teams that are playing close to their potential, but the one team that really "jumps off the page" should be the Los Angeles Dodgers who are TEN games below where they "should be".  Yes, the Cubs are playing well and will likely win their division, along with home field throughout the playoffs.  But, I would not be surprised if the Dodgers end up representing the National League in the World Series.  They have experience and much like the Indians in the American League, they are putting things together at the right time.

I also added the Rockies to this list because they are in close proximity to the Dodgers, as well as the two teams pushing for the Wild Card (Brewers, Cardinals). In my opinion, they are a classic case of a team "overachieving", as evidenced by their plus/minus figure (the polar opposite of the Dodgers).  With that said, which team is more likely to prevail in the NL West?

To close, anything can happen in a short playoff series, but sometimes when you look a bit deeper you find hidden meaning in the statistics. Will the trends that produced the listed figures continue in the playoffs? That is hard to say, but the best indicator of future performance is usually the past which bodes well for the teams like the Dodgers and Astros.

A 2018 World Series rematch anyone?