Infield Defense Changes with Three True Outcomes

Great defenders like Manny Machado may not be as important as they used to be (via Keith Allison).

Great defenders like Manny Machado may not be as important as they used to be (via Keith Allison).

The point wasn’t to make Andrelton Simmons’ defensive performance in 2013 seem even more impressive.

It ended up that way, but the idea was actually to show that infield defense has become less important over time. Let’s back up and examine the idea: three true outcomes have increased dramatically throughout baseball history thanks to the proliferation of strikeouts and a steady increase in home runs.

Of course, the inverse would then be true for balls in play—a plate appearance either ends in one of the three true outcomes (walk, strikeout or home run), or it ends with a ball in play. If three true outcomes are on the rise, balls in play must be on the decline.

First, let’s make sure the data bears this out. The graphs below show the home run, walk and strikeout rates throughout baseball history and then the summed three true outcomes and, inversely, the proportion of balls in play.

tto through history1

tto vs bip history

If it’s not entirely clear from the graph, 2013 came just shy of the record for the largest proportion of plate appearances ending in one of the three true outcomes at 30.32 percent, bested only by 2012’s 30.48 percent mark. While walks were down slightly to 7.9 percent (well below their 1949 high of 10.4 percent) and home runs were down to 2.52 percent (from 2000’s high of 2.99 percent), strikeouts reached an all-time high at 19.9 percent.

In all, these changes resulted in the second-smallest rate of balls in play ever, edging below 70 percent for just the second time.

The logic here should be easy to follow—fewer balls in play means fewer chances for fielders, decreasing the relative importance of defense compared to pitching and hitting.

Even if only the “modern” era of statistical tracking is examined, balls in plays are down from 72.3 percent in 2003 to 69.7 percent in 2013, a 3.7 percent decrease. The batted ball mix hasn’t shifted much in that time either, though we did see fewer outfield fly balls the past two seasons.

batted ball

What this shows, essentially, is that since 2003, the drop in balls in play appears to have impacted all fielders equally.

Unfortunately, data before 2003 is unavailable, but the stark drop in balls in play over time should make it clear that defense has become relatively less important—perhaps ground balls and hits on the infield were less prominent and this is just a shift back in the aggregate, but the increased rate of extra-base hits would lead us to believe the contrary, that infield defense was even more important in the last millennium.

In addition to fewer balls in play, though, teams have also moved to shift far more often. As Jeff Zimmerman outlined in The Hardball Times Baseball Annual 2014, shifting is in vogue. It makes sense, after all, since between 57 and 60 percent of pulled balls result in ground balls compared to 40 to 43 percent on balls hit to center and 22 to 27 percent on balls taken the opposite way. With advanced scouting and more data available, teams can better identify hitter tendencies and adjust with less risk. The fact that 24 hitters pulled at least 200 balls in play this year makes it even easier to do for the high-pull hitters (as Zimmerman notes, the top-20 players hitting into a shift accounted for over 2,500 plays in 2013, dropping their collective BABIP by 37 points in those situations).

Here are the number of each different type of infield shift last season, taken from The Annual:

2013 MLB Infield Shifts
Shift Type Total Shifts
Three infielders on one side 2,620
Middle infielder over bag 3,675
Third base to right 125
Other 110
Infield up 891
Total IF shifts 7,421

That’s more than 7,000 additional plays that decrease the relative importance of each infield defender. While that statement maybe doesn’t hold for each individual shift, a heavy-shift approach requires less range and decision making from fielders. Because it’s unclear which fielder made a play on each shift, they can’t be subtracted from the whole below, but the increased reliance on shifts furthers the argument that defense has become somewhat less important.

To dig down further, we took a look at infielders using some of the more advanced fielding tracking data we have available. Specifically, we looked at balls in zone by position and total plays made by position to see how the role of each position has changed. The shifts aren’t excluded, but note that “balls in zone with traditional infield” would be 7,421 less and “normal plays” would be significantly lower, too.

Balls In Zone and Total Plays Made By Infield Postion, 2003-2013
First Base Second Base Shortstop Third Base Infield
Season BIZ Plays BIZ Plays BIZ Plays BIZ Plays BIZ Plays Plays/PA
2003 6099 4484 11739 10356 10434 9203 10741 7413 32914 31456 16.78%
2004 5406 4070 12129 9863 11995 9872 9007 6215 33131 30020 15.92%
2005 5493 4343 12825 10403 12821 10484 9271 6813 34917 32043 17.20%
2006 6366 4799 12679 10401 13218 10809 10880 7686 36777 33695 17.92%
2007 6697 4965 12192 10120 13019 10625 10623 7221 35834 32931 17.46%
2008 6568 4860 12805 10525 12753 10567 10623 7403 36181 33355 17.78%
2009 6097 4766 12482 10149 13075 10476 9747 6943 35304 32334 17.28%
2010 6025 4602 12641 10380 12959 10354 10157 7220 35757 32556 17.55%
2011 6675 5299 12709 10394 12286 10087 10404 7366 35399 33146 17.89%
2012 6508 5166 12619 10181 12274 9850 10079 7238 34972 32435 17.61%
2013 6622 5312 12548 10049 12256 9843 9919 7197 34723 32401 17.53%

What’s interesting, though, is that while the number of plays infielders have made has varied, it’s been largely consistent over the past decade-plus. The percentage of plate appearances that result in an infielder making a play has actually gone up by three quarters of a percentage point.

IF Plays 2

Let’s take a closer look position by position.

First Base

Key Statistics, First Base, 2003-2013
Season Plays BIZ RZR wRC+ Off Def WAR
2003 6099 4484 0.735 112 338.1 -488.5 76.4
2004 5406 4070 0.753 109 250.3 -454.0 67.0
2005 5493 4343 0.791 112 338.6 -463.4 75.3
2006 6366 4799 0.754 113 345.9 -424.2 76.5
2007 6697 4965 0.741 111 248.1 -430.8 65.9
2008 6568 4860 0.740 110 222.7 -465.6 66.4
2009 6097 4766 0.782 115 388.7 -435.8 81.6
2010 6025 4602 0.764 112 280.9 -420.6 70.2
2011 6675 5299 0.794 112 268.6 -456.3 70.4
2012 6508 5166 0.794 107 118.8 -517.3 51.8
2013 6622 5312 0.802 110 195.6 -507.8 53.5

First basemen have actually seen their defensive workloads increase over the past decade, largely a result of the fielders simply making more plays on the balls hit their way. Perhaps this is due to teams moving their first basemen around more aggressively to cover greater ground, a greater reliance on pull-hitting pushing more balls to the corners, or simply a move to more athletic fielders. The net result hasn’t actually been better defense in the aggregate. Instead, first base remains a position played with an offensive premium and one that has seen a precipitous drop in overall value the past several seasons.

Second Base

Key Statistics, Second Base, 2003-2013
Season Plays BIZ RZR wRC+ Off Def WAR
2003 11739 10356 0.882 88 -344.3 52.4 57.2
2004 12129 9863 0.813 89 -329.7 76.1 63.1
2005 12825 10403 0.811 95 -113.8 128.6 86.6
2006 12679 10401 0.820 90 -311.2 -9.3 53.0
2007 12192 10120 0.830 94 -126.2 83.5 81.6
2008 12805 10525 0.822 95 -106.3 90.8 87.0
2009 12482 10149 0.813 95 -116.8 101.3 87.6
2010 12641 10380 0.821 94 -169.4 86.7 79.7
2011 12709 10394 0.818 91 -218.1 102.6 78.1
2012 12619 10181 0.807 88 -306.9 93.3 64.9
2013 12548 10049 0.801 91 -237.7 30.6 63.1

The second base renaissance appears to be at an end. From 2005 to 2010, the position became nearly a league-average offensive position, essentially becoming a duplicate of third base for a short time. Over the past few years, however, second basemen are making fewer plays on a similar number of balls while the position has reverted to an offensive weak spot. The result, like with first base, is a precipitous drop in the overall value of second basemen on both sides of the equation.

Third Base

Key Statistics, Third Base, 2003-2013
Season Plays BIZ RZR wRC+ Off Def WAR
2003 10741 7413 0.69 90 -364.7 77.8 61.2
2004 9007 6215 0.69 99 -52.5 31.4 87.3
2005 9271 6813 0.735 98 -103.2 28.4 82.4
2006 10880 7686 0.706 102 75.5 58.9 96.5
2007 10623 7221 0.68 99 -45.8 29.9 82.9
2008 10623 7403 0.697 100 -45.8 48.5 90.4
2009 9747 6943 0.712 98 -69.5 53.2 91.6
2010 10157 7220 0.711 97 -110.6 45.1 76.7
2011 10404 7366 0.708 92 -267.9 -29.2 60.8
2012 10079 7238 0.718 100 -27.5 52.6 90.6
2013 9919 7197 0.726 97 -148.3 48.3 76.1

Either the hot corner wreaks havoc on the statistics available or it’s quite a fickle position. The returns have fluctuated wildly at third base over the past decade, with offense at times nearing league average and defense swinging from incredibly valuable to a net-negative. The result, as you might expect, is an up-and-down overall value.

Shortstop

Key Statistics, Shortstop, 2003-2013
Season Plays BIZ RZR wRC+ Off Def WAR
2003 10434 9203 0.882 85 -386.5 214.2 61.3
2004 11995 9872 0.823 86 -335.7 233.5 66.2
2005 12821 10484 0.818 88 -284.1 216.9 75.1
2006 13218 10809 0.818 86 -375.2 224.6 63.4
2007 13019 10625 0.816 90 -247.8 224.6 76.9
2008 12753 10567 0.829 88 -321.9 240.3 72.2
2009 13075 10476 0.801 87 -357.5 220.3 69.7
2010 12959 10354 0.799 83 -418.4 253.7 64.6
2011 12286 10087 0.821 88 -297.2 213.2 73.7
2012 12274 9850 0.803 86 -322.8 252.4 72.9
2013 12256 9843 0.803 85 -324.4 209.6 64.1

As expected, shortstop is the most important defensive position in the infield. We saw earlier how shortstops have been edged by second basemen in terms of overall number of plays but the degree of difficulty is far greater at short. As a result, even with the worst offense of any infield position, shortstop has been the second most valuable position in terms of total wins added. Note, however, that the total defensive impact of shortstops was down in 2013, as it had the lowest mark in the sample.

The lede mentioned that Andrelton Simmons’ 2013 season would now look even more impressive, and it should — not only did he post the fourth-highest defensive runs total since 2003 and the second best at shortstop, he accounted for 31.6 of the position’s total 209.6 defensive runs, more than 15 percent. Manny Machado’s season looks even more incredible at third, too, as his 33.6 defensive runs represent nearly 70 percent of the position’s total. Given that some positions have negative defensive value, there are surely countless examples of players earning infinite portions of a position’s defensive value, but the point is that Simmons and Machado had outstanding defensive seasons at a time when their positions appear to be providing less overall value than in the recent past.

While balls in play are down overall, infielders haven’t noticed an appreciable change in their workload the last decade.final graph

The data doesn’t capture two key points: that prior to 2003, infield defense was likely even more important, and that while the numbers are steady, the increasing use of shifts likely makes some of the plays infielders do make easier. I’ll admit this runs counter to what I was expecting to find when I began researching the impact of three true outcomes on infielder defense. Obviously, then, the amount of plays made by outfielders is decreasing, a topic worthy of study for a future piece.

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Comments

  1. aweb said...

    Aside from walk-off homers and walk-off walks, those two outcomes should not be changing the total number of balls in play at all. Both of those outcomes affect the percentage of balls in play/PA, but that doesn’t change anything about how many plays the defense has to make eventually. 27 outs need to be recorded, only the K’s change how many the defense is involved in at a fundamental level.

    I.e., a game that results in nothing but HRs, BB, and GBs – no matter how many HRs and BBs are produced, the GB totals will be roughly the same (give or take a DB here or there).

    • Blake Murphy said...

      But with run environment down, there aren’t simply more plate appearances to work with, the contrary actually:

      2004-188,539
      2007-188,623
      2010-185,553
      2013-184,872

      Between that and IF changes, here’s how OF PLAYS look:

      2004-25,924
      2007-27,318
      2010-24,428
      2013-22,047

  2. Kevin R said...

    As you said, the workload of infielders has remained relatively constant despite the decrease overall in batted balls. I imagine that part of this reason is due to GB becoming a greater percentage of the batted ball distribution.

    Some teams are focusing on getting lots of ground balls; some are focusing on getting more fly balls. For those teams, infield defense and outfield defense, respectively, are incredibly important for maximizing run prevention from otherwise mediocre pitchers.

  3. Jon Roegele said...

    I can’t recall if Jeff touched on this in the Annual, but I wonder how fielders perform in general when they are in a shifted (i.e. Non-standard) position? As you say, it seems logical to think this should make it easier for infielders, but I wonder if there is a penalty associated with guys playing “out of position”? At least until shifting becomes common on their team.

    • Blake Murphy said...

      Yeah, that’s an interesting question. The required range obviously shrinks a great deal, but you could be moving in a way you’re not used to, first step is different, even the throwing angle.

  4. channelclemente said...

    What, if anything, does this mantra of ‘backspining’ a struck ball have to do with these changes. Logically, that should lead to more flyball outs, and flyballs. Alternatively, has moving to grass from artificial surfaces dictated a trend? Finally, what are the confidence intervals on these trend lines?

  5. pft2 said...

    So 132K BIP in 2013 If IF’ers made 32 K plays that means OF’ers are pretty busy. But according to B-Ref there were 63K PA to the IF with about 5K going for IF hits and 1.4K errors. I suppose P and C accounted for some plays but seems IF plays should be higher.

    What am I missing?

    • Blake Murphy said...

      Hmm, either the definition of plays is different between BR/FG. Note that what I’m using here is “plays” not “balls hit at” or “PA,” so there’s a lot of room for additional balls that weren’t hit to a particular fielder.

  6. Red said...

    Sounds like hitting is becoming less and less important also, since it takes fewer runs or less offense to win. Pitching is becoming less important too, since there’s such an abundance of it. The only thing with growing importance these days is the front office saber analysis. Championships are won and seasons are tossed out (Astros) before the regular season even starts.

  7. Greg Simons said...

    That last graph is quite telling. There were about 5,000 fewer balls in play in 2013 vs. 2003, but the infield BIP remained about the same. This would indicate that outfielders recorded 5K fewer plays, or about one play per team per game. That’s a notable reduction in OF plays, de-emphasizing the importance of OF defense.

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