Safety In Numbers: ISO Outliers


Last week, I looked into isolated power and compared it to batters’ walkrates with the idea that more patient hitters would be among the elite in isolated power standings. For the most part, that was correct. There were some batters who didn’t walk that much but still had strong ISO, and others who had hardly any ISO yet walked a lot.

In short, there’s a lot of variation in batters, approaches and skill levels. Surprising, right?
When I put my results into a scatter plot, I found a lot of no-walk, no-power guys (like Cesar Izturis or Juan Pierre) and a fair amount of no-walk, high-power guys (like Adrian Beltre or Alfonso Soriano) along with the elite batters who walk a lot and had a lot of isolated power (Albert Pujols, Jose Bautista, Joey Votto, Miguel Cabrera). But there was one little pocket of players that seemed to stand out as guys who walked a lot, relative to the rest of the league, and who had smaller levels of isolated power. I wanted to know more.

Outliers are always interesting. House, M.D. wouldn’t be as watchable if he just treated clinic patients with sore throats. Viewers tune in for the exceptional. That rare case that stumps everyone until a breakthrough solves the problem. Malcolm Gladwell wrote a bestselling book about the topic (and he himself is an outlier, being awfully brilliant). There might be better singers out there, but nobody notices them like they notice Lady Gaga. By one measure or another, they stand out and they’re fascinating.

I looked at those scarce players in the bottom right quadrant on the chart, where walkrates are the X-Axis and ISO is the Y-Axis (expressed as a percent above or below league average).  Then, to find one measure by which to compare the pool of batters for overall production, I checked their 2010 Runs Created in the Bill James Handbook and sorted by that figure:




Nick Markakis



Daric Barton



Joe Mauer



Ben Zobrist



Elvis Andrus



Brett Gardner



Michael Bourn



Johnny Damon



Jeff Keppinger



Jhonny Peralta



Cliff Pennington



Chone Figgins



Orlando Hudson



Yunel Escobar


Based off of the table, this group of batters would be considered fairly talented. They’re all names you know and have all produced for their teams. There are All-Stars and role players and they’re linked by a few similarities.

  • They hit very few homeruns – In fact, only five of these players have surpassed 20 homers in a season once in their careers.  Peralta did so three times but the last time was in 2008.  Mauer and Zobrist approached 30 in 2009 but that seems like it’s going to be a fluke for Mauer and Zobrist may have to wait a while to get back in that area, too.  Markakis and Damon are almost the same type of player – lefties who make good contact, have occasional pop and hit for a high average generally.  If you’ve played fantasy baseball anytime in the last five years, you’re still waiting for Markakis’s power to develop.
  • Base-stealing can make up for low ISO; so can walking A LOT –You’ll recognize some of the names as leadoff hitter types who do damage on the basepaths.  Since Runs Created considers steals in its formula, that’s how someone like Andrus can end up in the top five in RC while walking less than those around him and having hardly any power.  For those who don’t steal often, walking a lot is the other weapon they can use.  You notice a sharp dropoff from double digit BB%+ numbers after Damon and those batters who were closer to league average and also had low ISO numbers generally had lower RC counts.  Walking a lot made up for the lack of speed and power (see our old friend Daric Barton).
  • These batters make a lot of contact – Sure, it’s a small sample size in this case, but it’s part of a 150 batter sample so I feel okay drawing a conclusion from the fact that every player in the table had a better strikeout rate than the league average.  Every single one.  They combined patience with bat skills and got the bat on the ball.  Since you can’t get a hit without making contact, and since a ball in play always has a chance (at least) to become a hit, they had more hits on that basis than someone who might strike out more.  They weren’t swinging for the fences, but to drive the ball somewhere.

A general conclusion I want to make is this: a batter doesn’t need to have a strong ISO to be productive.  They don’t have to hit 20 homers a year either.  If you make contact and can draw a walk at a high rate, like the players at the top of the table, you’ll be among the better players in the league, despite barely getting double digit homers.  It helps if you can add in stolen bases.  It’s not a guarantee, though.  Part of the murkiness lies in how ISO is configured.  Since it’s total bases minus hits, then divided by at bats (more simply slugging percentage minus batting average), you can have a terrible batting average but a very strong ISO.

Let’s say a hypothetical batter comes to the plate 100 times.  In 80 of those at bats, he makes an out.  In the other 20, he hits a homer.  Let’s just assume no walks for simplicity’s sake.  He’ll have a line of .200/.200/.800/1.000 and isolated power of .600, which is ridiculous, but I’m demonstrating something so we’ll let the otherworldly number slide.

Now, let’s take a second hypothetical batter who also comes to the plate 100 times.  This batter will get out 70 times and will hit 16 singles, 12 doubles and two homers.  He’ll come out with a line of .300/.300/.480/.780.  That’s an ISO of .180, which is decent, but pales in comparison to the first batter.

Let’s say the first batter only has 1o homers and 10 doubles.  That’s a .200/.200/.600/.800 line.  The two batters will have a similar OPS but the first batter will have isolated power measuring .400, still more than twice the first batter.  I’d still rather have the second batter who makes less outs and still produces at a similar level when comparing the two OPS figures.  Just like any other statistic, isolated power is only one chapter in a player’s story, rather than the whole book.

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