16 September 2014

How I Learned to Stop Worrying and Love the Bomb

The Orioles are expected to clinch the AL East any day now so it makes sense to focus on the playoffs. One of the concerns about the Orioles in the playoffs is how our offense is reliant on the home run. Patrick Dougherty from Baltimore Sports and Life argued that this isn't a problem in this article. I figure it makes sense to write what seems to be an annual article taking a closer look.

A team that hits a home run is more likely to win a game than a team that doesn't. After all, runs scored via home run are just as valuable as runs scored via a different method. And if you score enough runs then you will win. One would expect a team that hits a home run in a game to win more often than a team that doesn't hit a home run. One way to see whether the Orioles are reliant on the home run is to compare their winning percentage when they don't hit a home run to the league average. Here's a chart.



2005-2014 2014   Orioles 2014
W 6,511 706 15
L 12,326 1,196 29

0.346 0.371 0.341

The average team from 2005 to 2014 won about 34.6% of the time when they didn't hit a home run. In 2014, the average team won 37.1% of the time while the Orioles only won 34.1% of the time. The Orioles have won about 1.5 fewer games than expected when haven't hit a home run. Given that our sample size is only 44 games this could be nothing more than a coincidence.

In contrast, the Orioles seemingly do very well in comparison to other teams when they hit at least one home run. As the graph shows, the average team wins nearly 60% of the time but the 2014 Orioles have won over 70% of the time.



2005-2014 2014   Orioles 2014
W 17,561 1,498 73
L 11,746 1,008 31

0.599 0.598 0.702

It seems clear that the Orioles do better than the average team when they hit a home run and do worse than the average team when they don't. It gets better because the 2014 Orioles have hit a home run in 70.3% of their games compared to the 2014 league average of 56.9%. The 2014 Orioles hit home runs more frequently than other teams and have a higher winning percentage when they do so.

The Orioles have a  .595 winning percentage and it may make sense to compare them to similar teams rather than the average team. This is complicated because the Orioles have hit a home run in 70.3% of their games while the average team hits a home run in 56.9%. It makes sense that teams with a higher winning percentage hit home runs in more of their games than the average team. It also makes sense that teams with a higher winning percentage would win a larger percentage of their games when they do or do not hit a home run compared to the average team. In order to compare them to a similar team it makes sense to account for both variables. The problem is that it's extremely difficult to do this using the Baseball Reference play index.

What is possible to do is determine how a team that has a .595 winning percentage would be expected to perform if it hit a home run in 57% of its games, if it hit a home run in 63% of its games and if hit a home run in 70% of its games. I can do that by determining how a team that wins an average amount of games would perform if it hit a home run for each of these three percentages and then simply multiplying by .595/the new winning percentage. So for example, a team that hit a home run in 70% of its games and won 60% of the games where it hit a home run and 37.1% where it didn't would win 53% of the time. So, I could figure out how a team that hit a home run in 70% of its games plus had a winning percentage does by multiplying the average win percentage by .595/.530. Here's a graph.



57% 2014 63% 2014 70% 2014 Actual 2014
No HR 0.441 0.43 0.416 0.341
HR > 0 0.711 0.692 0.67 0.702

This indicates that the Orioles win more often when they hit a home run than the average team with a .595 winning percentage and that the Orioles win considerably less often when they don't hit a home run. The average .595 team would probably go around 19-25 when they didn't hit a home run while the Orioles went 15-29. It seems that the Orioles are more dependent on the home run than the average team with a .595 winning percentage.

It seems that the Orioles do better than expected when they hit a home run and worse than expected when they do not. How does this translate to the post season?  The graph below shows how teams have performed from 2005 to 2014 when hitting a home run and not hitting a home run in both the regular season and post season.



No HR HR > 0 Chances of Hitting a HR
Regular Season 0.346 0.599 0.609
Post Season 0.36 0.586 0.619

Teams that do not hit a home run are slightly more likely to win in a post season game than in a regular season game. Teams that do hit a home run are slightly less likely to win in a post season game than in a regular season game. But the difference is minor. A team that hits a home run in either a regular season or post season game is likely to win and a team that doesn't is likely to lose.

It seems that the Orioles are likely to win the AL East and should be expected to face the winner of the AL Central in the first round of the playoffs. The following charts show how the Royals, Tigers, Orioles, and the average wins for each pitching staff when they allow at least one home run and when they don't.

 
Royals HR = 0 HR > 0
Orioles HR = 0 HR > 0
W 47 34
W 36 52
L 26 41
L 20 40

0.644 0.453

0.643 0.565







Tigers HR = 0 HR > 0
All HR = 0 HR > 0
W 44 38
W 1202 1018
L 20 46
L 711 1509

0.688 0.452

0.628 0.402

The Royals and Tigers are slightly above average when allowing a home run but lose the majority of their games. But the Orioles seem to have a secret ingredient that allows their pitching staff to give up home runs and still win.

Hitting home runs is a good thing and are even more likely to happen in the post season than in the regular season. Teams that can't hit home runs in the postseason are going to be in trouble. And if you're facing the Orioles then hitting home runs simply isn't enough. The Orioles overachieve when hitting home runs and underachieve when they don't. So, worrying about whether the Orioles are overly dependent on hitting home runs is a mistake. I recommend not to worry about whether this team hits too many home runs and just learn to love the bomb.

(Stats are accurate as of Sunday 9/14)

2 comments:

Anonymous said...

There is one nuance of the winning percentage when hitting a home run - the number of home runs hit in that game. I am willing to be that the Orioles have a lot more games where they hit multiple homers than the average team. If you looked at the games where the O's hit one home run compared to the league, it will probably be closer to the average.

Matt Perez said...

That's definitely part of it. The Os have went 29-20 (.592) when hitting 1 HR while teams in MLB have gone 834-748 (.527).

We're 17.4% better then the average club when we hit 1 or more HRs while only 12.3% better when we hit 1 HR. You'd win your bet.

But realistically you need to hit HRs to win in the playoffs. Being able to hit more than 1 in a game is a good skill to have.