The Arizona Diamondbacks and Intentional Walks

So far in 2016, the Diamondbacks are near the top for intentional walks issues to opposing batters this year - only the Braves have issued more than Arizona's 23. This is nothing new. The team was tied for the major-league lead year (curiously, also with Atlanta) and was equal-second in 2014. But the rate at which four fingers have been held up is sharply higher this season: in 2014 and 2015, the numbers were roughly the same, at 43 and 45 IBBs respectively. The current pace for 2016, if maintained, would have Arizona hitting sixty-two intentional walks by the end of the year, a jump of 38% on last year's numbers and only beaten by one team since 2011 (Giants 2013 = 64).

As we saw over the weekend against the Cubs, intentional walks don't always work. But is this one of those situation where we remember the times that it fails, and forget the more humdrum examples when the walk is followed by an inning-ending easy fly-ball to an outfielder? To find out the truth, I dug into all 23 examples of intentional walks issues by Arizona pitchers this year. Before we get to that, some interesting points regarding the breakdown of these:

• Brad Ziegler has more than anyone else; indeed, as many as any other two pitchers together. Through Sunday, he had thrown 4.4% of our innings (24), but issued 21.7% of the intentional walks (5).
  
• Meanwhile, Patrick Corbin and Zack Greinke have combined for 150 innings without an intentional walk. Indeed, Ziegler has as many IBBs this season, as Greinke has since 2011 (1064.1 IP).
• Perhaps surprisingly, most of these were not to reach the pitcher's spot: However, this may be tied to when they came in the game. The vast majority (14) were in the eighth inning or later, when a pitcher was unlikely to be hitting for themselves.
  
• We have yet to issue an intentional walk this year with no outs. The split is almost even between one out (10) and two outs (13).
• The most common score is with the Diamondbacks down by one run (8 times), followed by when the scores are tied (4). Again perhaps unexpectedly, we don't do it often to protect a lead; only on two occasions, both when up by one.

The chart below lists them all: data included the pitcher and hitter walked, the game situation, the base state after the walk, the hitter faced, the resulting play and the overall change in Win Probability (by Fangraphs), from before the intentional walk, to after the PA by the batter actually thrown to. This can be used to decided whether or not the intentional walk "worked": if it and the subsequent batter ended up improving the D-backs' chances of winning, it can loosely be called a success.

There is some evidence that selective memory is at work here. For overall, the tally of Win Probability resulting from intentional walks and the PA which follows them, is +54.8%. Woo-hoo! It's clearly a great tactic! But, wait... Almost all of that comes from a single case - the occasion against the Padres in San Diego, when we IBB'd the bases loaded with one out in the ninth, and Ziegler duly Ziegled.

Man, that was pretty as a picture. However, it was very much the exception; the 22 other intentional bases on balls this season, combined, added three percent to our chances of winning. In total, 13 of the 23 have improved that Win Percentage, 10 have decreased it, so outside of the above, it is not exactly moving the needle for Arizona massively, either way. This is a little against previous research. The Book: Playing the Percentages in Baseball concluded, "In terms of effects on the game outcome, we find that the negative from putting an extra runner on base usually outweighs the positive from facing a weaker batter," unless there was an elite hitter up, or to face a pitcher.

That said, some of the decisions by Hale seem strange, albeit in hindsight. Yeah, walking Stanton with two bases open and two outs to face Dietrich = no-brainer. But ever walking Erick Aybar, a man having one of the worst offensive seasons since the D-backs were born? [Just because it worked out, doesn't make it wise] Or walking a batter (even if it's CarGon) in order to face Nolan Arenado? Especially with only one down in the inning, that seems ripe for second-guessing. I suspect we'll see this continue as the season goes on: we'll remember the times it fails, and forget the occasions everything works as intended.