Why Jon Jay Is Overrated

This is the post that is going to make some people mad.  I can’t let that bother me.  People need to hear the other side of the argument, even if they don’t like it.  I certainly listen to the folks who think Jon Jay should be the Cardinals’ starting center fielder all the time.  I couldn’t disagree more and it’s time I explained why.

Jon Jay is not a bad player.  He is in my mind a 4th outfielder.  The bat that everyone thinks is wonderful, is in reality pretty blah.  Batting average, my friends, is not the measure of a good hitter.  It’s not even close.  People like to use it because it is what they understand, but as an evaluative tool it is not very useful.  Batting average measures quantity of hits, not quality, and it is quality that is most important.  Give me a .250 hitter who hits doubles, triples and home runs and I will take that every time over a .300 hitter who hits nothing but singles.  Jon Jay is the latter.  His batting average is as empty as the calories in a 2 liter Pepsi.

Let’s look at the numbers that show that.  The best stat for measuring how good a player is at hitting for extra bases is ISO or Isolated Power.  ISO is essentially slugging percentage (SLG) minus batting average.  The following table is an estimated ranking from Excellent to Awful of levels of ISO.  This table can be found here.


Rating ISO
Excellent 0.250
Great 0.200
Above Average 0.180
Average 0.145
Below Average 0.120
Poor 0.100
Awful 0.080



Jon Jay’s ISO currently sits at 0.082.  That ranks a hair above Awful on the above chart.  Now, to be fair, ISO at such small numbers of PAs is not predictive.  Fangraphs suggests a minimum of 550 plate appearances before ISO is predictive enough to draw conclusions.  So let’s look at Jay’s ISO during the last season he had at least 550 PAs, which would be 2013, where he had 628 PAs.  His ISO for 2013 was 0.095.  That ranks higher than Awful but just shy of Poor.  To be even more fair, let’s look at Jay’s ISO for his career.  That number is .106, which ranks just slightly above Poor.

Now let’s compare those numbers with those of Peter Bourjos, the other contender for the starting center field job.  Bourjos’ current ISO is .125 in 151 PAs (that’s compared to Jay’s 162 PAs).  Bourjos’ last season with at least 550 PAs was 2011; his ISO that season was .167.  Bourjos’ career ISO is .144.

However, there is more to evaluating a player than just his offense.  Defense counts too.  There are many who argue that Jon Jay’s defense has improved this season and some who cite his current UZR/150 of 10.2 and UZR of 1.2.  As compared to last season, those numbers are better.  However, those numbers in such small sample sizes are essentially meaningless.  To be at all predictive, UZR numbers must be evaluated using a minimum of 3 seasons.  An average of the 3 seasons is the best method.

Taking the average of Jay’s UZR numbers for 2011, 2012, and 2013 we get a number of -0.7.  That is slightly Below Average (Average is 0).

Another defensive metric used is Defensive Runs Saved (DRS).  Again, an average of 3 seasons of data is best for evaluative purposes.  Jay’s average DRS for 2011, 2012 and 2013 is -2.  That means Jay has cost his team an average of 2 runs with his defense.  Average being 0, Jay’s DRS is slightly Below Average.

Now let’s compare those numbers to Peter Bourjos.  Bourjos’ average UZR for 2011, 2012, and 2013 is +7.6.  His average DRS for those years is +6.6.

I shouldn’t think anyone would need numbers to know that Jon Jay’s arm is pretty bad.  That is kind of obvious from watching him throw.  However, for continuity sake I will tell you that his average ARM rating is -3.5.

So, all in all we have a player with a good batting average but poor ISO score, average to slightly below average range in CF and a below average arm.  As a starting center fielder, these numbers are not exactly a ringing endorsement.  The reader should also know that in 2013, the Cardinals’ outfield defense was one of the worst in MLB, with an outfield consisting of Matt Holliday, Jon Jay, and Carlos Beltran/Allen Craig.  It’s no wonder that John Mozeliak wanted to upgrade in this area.  That upgrade has essentially been nullified by manager Mike Matheny‘s insistence on continuing to use Jon Jay in the center field position primarily.

There will be those who will argue that Jon Jay’s presence in center field is necessitated by the team’s overall offensive performance.  I will argue that Jay’s contribution to the offense is marginal, given his very low ISO numbers.  Such a marginal increase in offense is offset by the more than marginal downgrade in defense he provides.

Jon Jay is a nice player as a 4th outfielder.  As a starter he is overrated.



Thank you for reading.





Leave a comment


  1. Bourjos’s BA is ,213 and SLG .338. Jay’s BA is .295 and SLG . 377. So Jay is out hitting him by over .80 points and out-slugging him by 40 points.

    So as I understand your argument, Bourjos’s hitting is somehow better? Because there is a greater difference between Bourjos’s BA and SLG?


    • No, that’s not my argument. My argument is that a high BA does not equate to a quality hitter. In cases like Jay’s with the very poor ISO, it equates to a prolific hitter of singles. Which is what he is. Not saying that is bad, just that it is not as great as the BA makes it sound.

      Look at Jhonny Peralta. He has a BA of .228 but has an ISO of .198. Folks like you look at that BA and say Peralta is a bad hitter. I say Peralta is a better hitter than Jon Jay because he hits for extra bases. It’s the quality, not the quantity.

      I used Peter Bourjos for comparison because he is the other CFer. He doesn’t hit because he only plays a few times a week. Bourjos doesn’t hit when he doesn’t play everyday and anyone who knows his history knows that. Even so, he has had more extra base hits with less ABs than Jay. Right now he is certainly not a better hitter than Jay, but his career hitting history suggests that he has the capacity to be a better hitter than Jay with enough playing time. That is, a better quality hitter, not necessarily a better quantity hitter. He is not going to get that playing time, so he is not going to hit.

      Jon Jay is overrated because people who don’t look beyond BA think he is a better hitter than he is. That was my argument, not that Peter Bourjos is currently a better hitter. He is an overwhelmingly better defender in CF though, which is why he should start instead of Jay, because Jay’s hitting is not good enough to overcome his defensive deficiencies.

      But don’t worry Bling, Bourjos isn’t going to start everyday, and probably will be gone at the end of this season if not before because of it. Then all will be right with the world, and we can all be content in the knowledge that Jay and his empty BA, lack of range and noodle arm will be there for all to enjoy unencumbered by better defenders.


  2. BW52

     /  June 15, 2014

    Jay is what he is.A singles hitter who might steal a few bases,hit .280 and play poor defense.I think the Cards have seen the best Jay has and it is what it is .Bourjos has more speed,better defense and more pop is his bat.Yet Matheny`s insistence of keeping Jay starting still hurts the team.


  3. I don’t really see the upside in either, but Jay’s skill set is more valuable to the team right now. I agree that Jay’s defense does negate his offense. Peter Bourjos is not in my mind an upgrade from Jay. The Offense is struggling so much that Jay has to be used more than Bourjos; what’s defense when they can’t get someone home………..


    • The upside is that Bourjos’ defense and speed is more valuable to the team than Jay’s offense.

      Bourjos .5 fWAR
      Jay .3 fWAR

      The other upside is that Bourjos will hit better if he plays everyday.


  4. Laura Michaels

     /  July 3, 2014

    You can throw out as many negative statistics about Jay as you want. I’m sure a pro-Jay, anti-Bourjos fan could find just as many stats making Bourjos look like a poor choice. Jay gets on base, singles hitter or not. He adds a spark and makes things happen! I’m glad Mike Matheny recognizes his value and doesn’t focus on ISO and SLG percetanges alone. Management knows what they are doing, whether or not we as fans understand the reasoning or not. There is so much more behind the scenes info. we never even know. All that I’m saying…is give Jay a chance!


    • I respect your opinion. However, Jay is what he is. He will never be anything more than he is now, he has reached his ceiling. We have seen the best of Jon Jay, and to me it is not good enough. His defense is incredibly average and his bat has no pop. He is a nice, but unexciting player. As for Mike Matheny’s opinions, they are not credible to me. This is a man who thinks Daniel Descalso is a good player.

      Peter Bourjos, on the other hand, has much more upside. His issues in his career have had to do with lack of playing time either because he was blocked by another player or he was injured. When he got regular playing time, he was a 4 WAR player. Jon Jay has never been that valuable in his career. Bourjos is younger, and much more talented. His offensive issues this season are because he has not been given sufficient playing time to get into a rhythm at the plate. The introduction to a new league held him back at first, and the struggles of the rest of the team kept him from getting the chance to play enough to get his bearings offensively. Having watched both Jay and Bourjos play for the last three seasons, there is no doubt in my mind that Bourjos is the better player. He is an elite defender, incredibly fast, and has more pop in his bat than Jay. He may not hit for as much average, but batting average is an overrated statistic that is on its way out as a measure of offensive performance.



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