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I'm old school...

soupcan Aug 16 2006 09:39 AM

...and maybe a little dense. Perhaps somebody here can educate me. When looking at a player and trying to determine his worth I look at batting average, home runs and rbi. I know what those numbers mean and what are 'good' numbers for whatever type of player I'm looking at. Within the last few years I have come around and started to look at OBP, SLG and even more recently, OPS. I understand how to calculate these numbers and I'm getting an understanding of what 'good' numbers are as opposed to bad. What I don't understand is exactly what OBP, SLG and OPS measure. I assume that OBP measures the percentage of times a player reaches base per AB. So if Babe Ruth's career OBP is .474, Ruth reached base almost half the time he strode to the plate. Is this accurate? For SLG Babe Ruth's career number is .690 does this mean that Ruth collected 6/9ths of a base for each AB? OPS is just a mystery to me. I know that it is gotten by adding OBP and SLG and I understand that an OPS of .900 or higher is elite but what exactly does the number mean? 90% of what?

Elster88 Aug 16 2006 09:44 AM Edited 2 time(s), most recently on Aug 16 2006 09:47 AM

OBP is basically batting average augmented by walks. It's hits plus walks divided by plate appearances (with plate appearances being all at-bats and walks). So instead of it being number of times a hitter reaches base per at-bat, it's the number of times per plate appearance. SLG is supposed to measure power. A batter gets 1 for every single, 2 for every double, 3 for every triple, and 4 for every homerun. Divide that total by at-bats. So the answer to your question is yes, .690 means 69/100 of a base per at bat. For OPS I usually just add the two together, though there may be a more precise mathematical formula. In any event my OPS has never been more than .001 different than the one given on a website. AFAIK, there's no way in words to describe it in terms of "90% of something".

Benjamin Grimm Aug 16 2006 09:45 AM

I haven't fully embraced these new numbers either. (I know that I would have loved all of these stats when I was a teenager.) I think your math is a little bit off on Babe Ruth's slugging percentage. The .690 means he averaged 69 total bases for every 100 at bats. (6/9 would be .667.) As for OPS, it's not a percentage, it's the sum of two percentages. I never understood the rationale behind that, other than that's it's an easy way to look at two percentages at once. The .900, though, doesn't mean 90 per cent of anything.

seawolf17 Aug 16 2006 09:47 AM

Yancy Street Gang wrote: As for OPS, it's not a percentage, it's the sum of two percentages. I never understood the rationale behind that, other than that's it's an easy way to look at two percentages at once. The .900, though, doesn't mean 90 per cent of anything. That's my problem with OPS. It doesn't mean anything; you're adding two fractions with different denominators and treating them as equal, and they're not. That's why I always liked the other, more mathematically nice numbers, like TA and ISO.

Frayed Knot Aug 16 2006 09:49 AM Edited 1 time(s), most recently on Aug 16 2006 09:52 AM

]I assume that OBP measures the percentage of times a player reaches base per AB. So if Babe Ruth's career OBP is .474, Ruth reached base almost half the time he strode to the plate. Is this accurate? Yes. A good way of thinking about OBP is that is shows you the pct of time the batter does NOT make an out. That's why it's more important than plain old BA. ]For SLG Babe Ruth's career number is .690 does this mean that Ruth collected 6/9ths of a base for each AB? Accurate yes (although it's 69/100 not 6/9), but that's kind of an odd way of thinking about it. SLG is a better metric than BA because it doesn't just count the hits but gives the batter extra credit for the big ones. Since BA treats all hits alike it's a bit like saying that my handful of nickels & pennies is worth more than your quarters and dimes simply because I have more of them. Counting each coin's worth (SLG) gives us a better measure. ]OPS is just a mystery to me. I know that it is gotten by adding OBP and SLG and I understand that an OPS of .900 or higher is elite but what exactly does the number mean? 90% of what? The number itself doesn't really mean anything in this case; it's merely the sum of the other two. Since the others look at things from a different angle (OBP measures how often, SLG measures how well) it's like putting together two one-legged creatures in an effort to walk better.

Elster88 Aug 16 2006 09:49 AM

I think the method to the madness is an attempt to find what leads to the most runs scored. Someone on this forum posted what stats most closely correlate to runs scored. I'm pretty sure OPS heads the list. I'm trying to get a handle on them myself, but I am in the dark too as to what an "average" OPS would be, and how closely players are distributed around the mean. It would help if any website anywhere posted the average OPS. I've only seen lists of Top 100 at most.

metirish Aug 16 2006 09:49 AM

I found this answer online.... ] In baseball statistics, on-base plus slugging (denoted by OPS) is the combination of on base percentage (OBP) and slugging average (SLG). This statistic combines both the ability of a player to get on base and to hit for power. It is very popular in measuring the offensive worth of a player. An OPS of .900 or higher in [[[Major League Baseball]] puts the player in the upper echelon of offensive ability. Typically, the league leader in OPS will hover near the 1.000 mark. OBS = AB(H+BB+HBP) +TB (AB+BB+HBP+SF)/AB (AB+BB+HBP+SF) where: H = Hits BB = Bases on balls HBP = Times hit by pitch AB = At bats SF = Sacrifice flies TB = Total bases Total bases refers to the number of bases a player has gained with hits, i.e. the sum of his/her hits weighted by 1 for a single, 2 for a double, 3 for a triple and 4 for a home run. Only bases from safe hits count toward this total. Total bases can be calculated from commonly used baseball statistics by using the formula TB = 1B + 2x2B + 3x3B + 4xHR.

Benjamin Grimm Aug 16 2006 09:50 AM

I understand the urge to want to merge OBP and SLG, but adding them together does seem overly simplistic.

Elster88 Aug 16 2006 09:53 AM Edited 2 time(s), most recently on Aug 16 2006 10:01 AM

The SS Comp thread reminded me of another difficulty I have with new stats. When is there a siginificant difference between two OPSs? Is .002 a big difference? How about .020? .050? etc.

Frayed Knot Aug 16 2006 09:56 AM

Yancy Street Gang wrote: I understand the urge to want to merge OBP and SLG, but adding them together does seem overly simplistic. It is - but the quick & easy-ness of it all is why it's caught on. There are those who'll argue that sticking a coefficient in front of the OBP portion (often 1.4) gives you a better guide OPS' = 1.4* OBP + SLG

Johnny Dickshot Aug 16 2006 09:56 AM

OPS is just a quick and dirty way of expressing the two. True seamheads tend to weigh OBP higher than slugging in terms of run value, but as a q&d measure, its easy to do. OPS correlates pretty well to run values and is easy to calculate so that's why its used. You guys are old school. Batting average is a silly rate stat created back in the 19th century when hitting was more about placing the ball “scientifically” like making a pool shot or a tennis stroke. And in truth hitting wasn’t even “about” that, but that that style was favored by the stat’s inventor, Henry Chadwick. That it lasted as long as it had as the ultimate expression of a player’s hitting ability is a testament to Chadwick’s PR. The eureka moment for me and OBP came when I reverse-engineered it to “out percentage.” A guy with .300 OBP makes outs 70% of the time -- .400 OBP = 60% outs. It helped me see the light.

Elster88 Aug 16 2006 10:02 AM

Seamheads is a new one to me.

Frayed Knot Aug 16 2006 10:17 AM Edited 1 time(s), most recently on Aug 16 2006 01:57 PM

Another good measure of power is IsoP (Isolated Power). It really shows raw power better than SLG because, since BA is the basis for SLG, the player with the higher BA has a head start in SLG even if he's not a very good slugger. IsoP simply shows the difference between BA & SLG -- iow, it's SLG with all the singles taken out. As an example, in 2004 (his first year w/the Mets) Mike Cameron had a very similar SLG to Ichiro (MC = .479, IS = .455) so that a quick look tells you that they were similar sluggers when, in fact, they are anything but. That was the year Ichiro hit .372 - so his IsoP was just .083 (.455-.372) as nearly 86% of his hits (225 of 262) went for singles Cameron's .479 slugging was off of a BA of just .231 - giving him an IsoP of .248 -- as just 53 of his 114 hits (46%) were singles The other thing to remember is that no one stat tells you everything. OPS has gained acceptance because it correlates best with runs scored (ie, teams with the highest OPS will usually the most runs more often than the team with the best OBP, which rates higher than SLG, which trumps BA, which in turn is better than say SBs)

Frayed Knot Aug 16 2006 10:53 AM

For perspective purposes: 2005 NL AVGs: BA = .262, OBA = .330, SLG = .414, OPS = .744, IsoP = .152 Lg Leaders: BA = .335 (D Lee). OBA = .445 (T Helton), SLG = .662 (D Lee), OPS = 1.081 (D Lee) 2005 AL AVGs: BA = .268, OBA = .330, SLG = .424, OPS = .754, IsoP = .156 Lg Leaders: BA = .331 (M Young), OBA = .440 (J Giambi), SLG = .610 (A-Rod), OPS = 1.031 (ARod) And for kicks ... 1968 NL AVGs: BA = .243, OBA = .300, SLG = .341, OPS = .641, IsoP = .098 Lg Leaders: BA = .335 (P Rose), OBP = .391 (Rose), SLG = .545 (W McCovey), OPS = .923 (McCovey) 1968 AL: AVGs: BA = .230, OBA = .297, SLG = .339, OPS = .636, IsoP = .109 Lg Leaders: BA = .301 (C Yaz), OBA = .426 (Yaz), SLG = .552 (F Howard), OPS = .922 (Howard)

MFS62 Aug 16 2006 10:56 AM Edited 1 time(s), most recently on Aug 16 2006 10:56 AM

didn't they lower the mound after the 68 season? Later

Elster88 Aug 16 2006 10:56 AM

]SLG = .610 (A-Rod), OPS = 1.031 (ARod) Amazingly enough, all of his hits were in non-pressure situations.

Frayed Knot Aug 16 2006 11:01 AM

MFS62 wrote: didn't they lower the mound after the 68 season? Yup. I picked that year specifically to give some contrast as it was probably the most pitching dominated one since maybe the Woodrow Wilson administration. They raised the mound in '69, then let the DH in 4 years later - and both were, at least in part, a reaction to the stranglehold the pitchers had gained on the game.

MFS62 Aug 16 2006 11:13 AM

Frayed Knot wrote: ="MFS62"]didn't they lower the mound after the 68 season? Yup. They raised the mound in '69, Nope, they lowered it - by 5 or 6 inches. It was felt pitchers got too much leverage throwing "down" from the high mound. Later

Frayed Knot Aug 16 2006 01:35 PM

D'oh! I meant lowered. From 15 inches to 10

soupcan Aug 17 2006 07:09 AM

I appreciate all the responses. Thanks.