Intentional walk part II

So in the previous post I ran the number for a league average eighth place NL batter and a league average pitcher and found that you should not intentionally walk the eighth place batter unless there were runners on second and third with two outs.

In this post I am going to expand those results over almost a complete range of batters. The concept is still the same so if you have any question about how this is done read the previous post. The only difference is now I ran the code over a range of OPS's from .200 to 1.000. This range should encompass all but the worst hitting pitchers to all but the most elite batters. The results can be interpreted using a three dimensional graph. We will start with a runner on third and two outs.

On one axis we have the current batter's OPS and on the other axis the next batter's OPS with the difference of intentionally walking the batter and pitching to him on the vertical axis. This is basically a flat surface, or plane, that slopes downward. Where that plane crosses zero on the vertical axis the expected runs from both options are the same. That means it doesn't matter if you walk the current batter, or pitch to him, both options will produce exactly the same amount of expected runs. We call this the break even point. Things are a little hard to see on this plot so I am going to instead show you the view from above and things should be a little clearer.

This is like looking at a elevation map of the US. Colors close to red on the spectrum represent large values or mountains on the map. Colors close to violet on the spectrum represent low values or valleys on the map. This graph works the same way. The red area in the lower right means the difference between intentionally walking the batter and pitching to him is high (or very bad). This makes sense because this area is when the on deck batter has a very high OPS and the current batter has a low OPS. The opposite area is where you have a strong batter up now but a very weak batter on deck. The break even line is shown and each color band represent .03 of an expected run.

If the MC was doing a perfect job you would expect these color bands to be straight lines but you can see some small kinks in them. No matter how many trials you run no MC will perfectly match the data but the more trials run the closer it will come. I am planning on rerunning with ten million trials to see if I can straighten out those lines even more but that won't be done for a few days. From our numbers from the last post we know that a batter with an OPS of .707 and an on deck batter of .362 should be close to the break even line but slightly positive which you can see on this graph. The next situation is a runner on second with two outs. Again from our numbers from yesterday we saw that these two values were very close so we should be expecting our graph to be very similar and it is.

If you look very closely you can see a tiny difference in the two graphs but they are basically the same. Again, with a league average eighth placed batter and a league average pitcher on deck you shouldn't intentionally walk the batter which is shown on the graph. So lets move on to the situation where there are runners on second and third with two outs. When should you go ahead and load the bases?

This graph shows some differences which again we expected looking at the numbers from yesterday. Our break even line is lower at the start but rises much quicker and goes off the graph further to the left than the others. What this is saying is if this situation is much more dependent on the on deck hitter than the other two. If he is a very poor batter then you really want him at the plate. But once he becomes even somewhat competent then loading the bases becomes too risky of a play. So basically only do this if the pitcher is coming up.

So I am planning on adding some graphs like these to the statistics page but I want to increase my trials and then I might was well run over all situations to see just how large a difference you need to do something crazy like walking Barry Bonds with the bases empty. This will take a few days for me to sort out and I won't have a chance to work on this until Tuesday so look for another post on this Wednesday or Thursday. Hopefully though I will have a special update Sunday night or Monday that you shouldn't miss.