Often, we fall into the trap of thinking that OBP = plate
discipline and walks, while SLG% = power. In reality, both OBP and SLG% are
largely made up of batting average. For a league average player, hitting
.260/.330 per se, the batting average makes up nearly 4 fifths of the OBP. Even
for an extreme on-base guy, hitting say .220 with a .350 on-base, the average
still accounts for nearly 2 thirds of the OBP. As for slugging, a player’s
average contributes over 50% of their SLG% (apart from extremely unusual examples,
such as Jose Abrau). In other words, the bread and butter of a player’s OBP and
SLG% is batting average.
The reason that analysts idolise OBP is not because ‘taking
a walk’ is of specific value over and against hitting a single. It is base
runners that are so valuable. Therefore, as OBP measures the percentage of
times you become a base runner (whether by hit, walk or HBP), it becomes a
valuable calculation. A player is not valuable simply because he takes a walk;
he is valuable because he reaches base. Of course, a player with a high batting
average will have a high on-base, whether or not he walks at a high clip. And
such players are still valuable.
So if OBP and SLG% both largely consist of batting average,
then there is tremendous overlap between what they measure. While OBP and SLG%
have distinctions in what they record, the majority of their measurements
overlap. Indeed, for some players, the overlap is stretched. A typical ‘singles
hitter’ will find that their OBP and SLG% are similar (in some cases, OBP is
higher). Their OBP is naturally measuring their average plus walks, whilst
their SLG% is merely measuring their average plus occasional extra base hits.
So for that breed of player, the SLG% is really just a slightly inflated
batting average. SLG% only becomes a significant measure for players who can
use the power to produce a decent separation within their slash-line.
All this produces an issue with OPS.
If you accept these 2 premises:
- That around 75% of a player’s OBP is typically comprised of their average.
- And that over 50% of a player’s SLG% is comprised of their average.
Then, OPS records a player’s batting average twice. Every
time a player gets a hit, it contributes to both their OBP and their SLG%. Thus each hit will be represented twice in
the player’s OPS! Each walk will be recorded once, as will base beyond 1st.
But the reaching of 1st base (via a hit, double, triple or homer)
will be recorded twice. This means that OPS unequally weights batting average
as twice as valuable as any of the other elements that contribute to the stat.
Take a player whose offensive contribution rests primarily in
their average. Players who don’t walk much, or hit for much power such as Juan
Lagares, Ben Revere, Darwin Barney, Jon Jay, Zack Cozart or Adeiny Hechavarria
(hardly MVP material, I realize, but everyday major league players nonetheless).
Their OPS is little more than their batting average doubled.
Revere is hitting .290 with a .662 OPS. Of that OPS, .580 is
batting average. That means that only 8% of Ben Revere’s OPS comes from outside
of his average. Admittedly, OPS was not formulated with Ben Revere in mind. But
with power on the decline, the typical major league player is increasingly
deriving his OPS from the doubling of his average. This uncovers an increasing
issue with the use of OPS.
However, OPS has a place. If only it could be re-thought, it
would more accurately measure what it attempts to value. The value of OPS was
that it attempted to combine multiple aspects of offence into one number. More detailed
stats such as WAR and wRC+ have since taken this to another level. But the aim
of OPS is honourable. It takes more into account than the individual elements
of the traditional slash line. OPS acknowledges that these individual elements
are lacking, and therefore have weaknesses. Let me explain.
·
Average: the weakness of batting average is that
it only accounts for one means of reaching base (albeit, the most important one).
Also, an infield single and a grand slam are weighted equally within a player’s
average.
·
OBP: On-base, unlike average, records all
base-reaching skills. Measuring ‘base reaching’ is valuable. However, like
average, it does not distinguish between the value of the bases reached,
whether singles, doubles etc.
·
SLG%: Slugging is, of course, a record of the
number of bases reached per at-bat. However, the picture is incomplete. It does
record singles, but not walks, despite the fact that both result in a player
reaching 1st.
All these stats paint a picture of a player’s contribution. But
in each case, the picture is lacking. In the case of OPS, the picture is
overcrowded, recording average twice. But what if you could produce a simple
metric where each base was included, yet only once?
Here are all the elements needed:
- Walks
- Hits
- Extra base hits
- HBP
Also, stolen bases should be included. There is a reason
that doubles are more important than singles. Extra base hits increase the
chances of producing a run, moving the runner into scoring position. Yet a
stolen base functions this way also. In most cases, the value of a double is
equal to the value of a single plus a steal (just as, in most cases, a single
is equal to a walk in value). Therefore, if we are going to reward extra bases as
more valuable than singles, then stolen bases ought to be recognized.
Adding all these elements together would give us the number
of bases reached per at-bat, whether those bases were reached by walk, single,
double, homer or steal. Each base is valuable, thus each base should be
measured. The more the merrier. This would be like adding steals, walks and HBP
to a player’s total bases.
We might call this a measure of ‘bases per bat’ (or BPB).
Let’s use an example.
A player has 550 at-bats. He produces:
- 100 singles
- 30 doubles (60 bases)
- 10 triples (30 bases)
- 20 home runs (80 bases)
- 40 walks
- 10 HBP
- 40 steals
(These are Carlos Gomez’ impressive 2013 stats, rounded for
convenience).
The number of bases reached by his own merit is 360 (I
realize that going 1st to 3rd and scoring from 2nd
are also valuable skills in advancing through the bases, yet these are
dependent upon the contribution of another batter).You could use net steals, as
a single followed by a caught stealing is roughly equivalent to making an out
at the plate. If you divide those 360 bases by his 550 at-bats, you get .655.
This number is significantly different to Gomez’ OPS of nearly .850, but more
evenly and consistently reflects the total value of the bases he merited
through a season’s work.