OPS: Be Gone!

OPS, 2OPS, 3OPS... what should you use?

By Tangotiger

Team of same players

The following table presents various theoretical teams that are equivalent in expected Runs Per Game. The teams range from high-walks, low-power to low-walks, high-power. The equivalency is based on BaseRuns. If someone wants to run these teams through their favorite simulator, we should expect these teams to also be equivalent.

 

PA	AB	H	2B	3B	HR	BB	Outs	AVG	OBA	SLG	BsR
620	600	160	46.6	6.2	24.9	20	440	0.267	0.29	0.489	75.6
640	600	160	37.7	5	20.1	40	440	0.267	0.313	0.447	75.6
660	600	160	30	4	16	60	440	0.267	0.333	0.41	75.6
680	600	160	23.4	3.1	12.5	80	440	0.267	0.353	0.378	75.6
700	600	160	17.6	2.3	9.4	100	440	0.267	0.371	0.351	75.6
720	600	160	12.4	1.7	6.6	120	440	0.267	0.389	0.326	75.6

Assuming that all these teams are equivalent, what metric can you construct using only OBA and SLG? The best-fit equation among the above samples is: 1.56 * OBA + SLG. Here is how OBA+SLG (OPS), the best-fit, and 3*OBA+SLG (3OPS) look:

 

AVG	OBA	SLG	OPS	Best-Fit	3OPS
0.267	0.29	0.489	0.78	0.942	1.36
0.267	0.313	0.447	0.759	0.934	1.384
0.267	0.333	0.41	0.743	0.93	1.41
0.267	0.353	0.378	0.731	0.929	1.437
0.267	0.371	0.351	0.722	0.93	1.465
0.267	0.389	0.326	0.715	0.933	1.493

This table shows that OPS undervalues teams with high OBA, and overvalues teams with high SLG. 3OPS does the reverse: it overvalues team's with high OBA, and undervalues teams with high SLG.

Team of real players

However, this is if you have a team of players that end up producing the above totals. The impact of a player with the above profile, inserted into a typical current team, will not be similar. Let's construct some new profiles of players, and insert them into a team of 8 typical profiles, so that these new teams of 9 players are all equivalent. (This will more closely resemble the real-world scenario.) Note that the team totals were all fixed to 3960 outs.

 

PA	AB	H	2B	3B	HR	BB	Outs	AVG	OBA	SLG	BsR	LWTS
655.3	634.2	169.1	44.4	5.9	23.7	21.1	465.1	0.267	0.29	0.467	76.5	-3
657.7	616.6	164.4	37.2	5	19.8	41.1	452.2	0.267	0.313	0.439	76.5	-1.3
660	600	160	30	4	16	60	440	0.267	0.333	0.41	75.6	0
662.2	584.3	155.8	23	3.1	12.2	77.9	428.5	0.267	0.353	0.379	73.8	1
664.2	569.3	151.8	16	2.1	8.5	94.9	417.5	0.267	0.371	0.347	71.1	1.8
666.2	555.1	148	9.2	1.2	4.9	111	407.1	0.267	0.389	0.314	67.3	2.3

You will notice that the BaseRuns of these players are not the same. This is because within the context of their teams, they do have the same impact, but if they were part of a team where all the players were like them, they would not have the same impact. I also present an extra column, Linear Weights, which also shows that there is some disagreement in how it interprets these players.

Not presented here is the teams of each of these players with the 8 typical players. It's boring to look at. Just take it from me that these team BaseRuns are all the same.

Ok, so what we have here are 6 distinct types of players, all of which, if they were inserted into a typical current team of 8 typical players, would have each of their teams scoring the same number of runs. Now, let's find the best-fit equation. To make all these players equivalent using only OBA and SLG, the best-fit equation is: 1.64 * OBA + SLG. Here again is how OPS, the best-fit, and 3OPS sees these players.

 

AVG	OBA	SLG	OPS	Best-Fit	3OPS
0.267	0.29	0.467	0.758	0.944	1.338
0.267	0.313	0.439	0.752	0.952	1.377
0.267	0.333	0.41	0.743	0.957	1.41
0.267	0.353	0.379	0.732	0.958	1.438
0.267	0.371	0.347	0.719	0.957	1.462
0.267	0.389	0.314	0.703	0.952	1.481

Conclusion

The best-fit was based on these 6 samples of players. These are not representative of all players. If you really wanted to find the best-fit among actual players, you'll have to repeat what I did (inserting each player into a team of 8 typical players), but for a much larger sample. I would expect the best-fit equation to fall somewhere between 1.5 and 2.0. If you must rely only on OBA and SLG to establish a player's current run production, it would probably be easiest to do 1.5*OBA+SLG.