The vacuum doesn't allow for the influence of spin, as well.
Optimum launch angles have changed in golf over the last 30 years. In my experience, it used to be that a boring trajectory produced the longest shot. The ball used to spin more off the driver so balls launched with high trajectories tended to just balloon.
Today, the ball is designed to spin less off the driver but more off of irons, where you want spin to stop the ball on the greens. Balls launched with the higher trajectory with the driver now carry more and ballon less.
It was on that experience that I thought almost all homers would fall into a seemingly narrow trajectory window.
Very interesting that it is the most "moon-like" or "vacuum-like" park in the majors that rewards the highest launch angles.
I've played most of my golf life in "coastal air." Inland there is a difference. Not only on the coast are you likely at a lower altitude (more air) but it tends to be cooler and denser for much of the day/year. Especially mornings and evenings.
I'm willing to bet that were it really closely studied you would find an impact of tides, in fact. Huge amounts of air move in and out with the tides. Esoteric stuff, I know. But I bet it could be measured.
Honest to flippin' goodness, is there another baseball site that does this kind of stuff? You guys are too great! I think I will name my first born male child after all you guys. Good old DocGMojMattDaddyPhxBat his buddies will call him. The kid will clearly have issues. But then none of his 3rd grade friends will know what in the heck BABIP is, either. Losers he will call them.
moe
ESPN’s Hittracker.com is a Web site that measures the physics of home runs. It measures trajectories and speed off bat, and charts the parabolas of these home runs. Yesterday, we were playing with Hittracker, and noted which players hit the ball the hardest. Doc noted that Seager was not the best on the Mariners at producing speed off the bat.
I countered by showing that Seager always had nice drive launch angles for his home runs.
Moe, who is a golfing whiz, noted that every home run is probably a nice line drive. I thought that that couldn’t be true since 45 degree launch angles carry significantly farther, and decided to test this out.
Consider the title graph, which I stole from Wikipedia:
It is one of the laws of physics that a 45 degree trajectory or launch angle produces the longest range of a projectile for a set launch speed. A 60 degree launch and a 30 degree launch produces ranges of 87 percent of the 45 degree trajectory, but in much different ways. A 30 degree trajectory travels in a more or less straight flight path while a 60 degree trajectory is a towering parabola that touches down at the exact same place as the 30 degree trajectory. What the 60 degree trajectory gives up in efficient path forward it makes up in height to fall. One is not preferable to the other.
At least that is how it works on the moon, where there isn’t such a thing as air and wind resistance. Physicists call this “in a vacuum”. Since they don’t play baseball on the moon yet, here is how this plays out on Earth:
Hittracker states that there have been 2,525 home runs hit in 2014. I expected home runs to vary, with launch angles of up to 60 degrees, and some hitters to show trends of launching higher than others. I suspected that this might be what was wrong with Justin Smoak, that his launch angles were too high. The results were surprising, and Moe: I will never doubt you again.
Out of 2,525 home runs, the highest trajectory a home run has occurred was 45 degrees.
This was hit by Jose Abreu, in Coors field, the most moon like of MLB ball parks. There have been no other 45 degree home runs. Out of 2525 home runs, only 12 of them have been at trajectories of 40 degrees or above. Three of these have been at Coors field. Coincidence? I don’t think so. Observe:
| Date | Player | Field | Distance | MPH off bat | trajectory | |||
| 4/8/2014 | Video | View | Abreu, Jose | Coors Field | 353 | 97.1 | 45 | |
| 7/7/2014 | Video | View | Rizzo, Anthony | Great Americ... | 347 | 99.9 | 42.7 | |
| 6/5/2014 | Video | View | Goldschmidt, Paul | Coors Field | 366 | 101.3 | 42.2 | |
| 3/31/2014 | Video | View | De Aza, Alejandro | U.S. Cellula... | 378 | 100.3 | 41.7 | |
| 5/2/2014 | Video | View | Abreu, Jose | Progressive ... | 359 | 103.9 | 41.7 | |
| 5/3/2014 | Video | View | LaRoche, Adam | Citizens Ban... | 336 | 98.2 | 41.1 | |
| 7/5/2014 | Video | View | Peralta, Jhonny | Busch Stadiu... | 362 | 102.9 | 40.6 | |
| 7/9/2014 | Video | View | Rizzo, Anthony | Great Americ... | 368 | 103.3 | 40.3 | |
| 5/28/2014 | Video | View | Carter, Chris | Kauffman Sta... | 370 | 103.1 | 40.2 | |
| 6/9/2014 | Video | View | Choice, Michael | Globe Life P... | 357 | 100.5 | 40.2 | |
| 4/5/2014 | Video | View | Arenado, Nolan | Coors Field | 385 | 99.1 | 40 | |
| 6/17/2014 | Video | View | Davis, Chris | Tropicana Fi... | 319 | 93 | 40 | |
The other 2,513 home runs had what I would consider line drive trajectories of less than 40 degrees.
Takeaway Points:
1. A 30 degree trajectory travels through significantly less air than a 45 0r 60 degree trajectory to get to roughly the same place.How much less? A 60 degree trajectory travels 1.28 times as far to land at the same place as a 30 degree trajectory. A 45 degree trajectory travels 1.265 the distance of a 30 degree trajectory to get 13 percent further downrange. At least that is according to my scratch pad math which is always suspect. Air restistance is a bigger deal than I thought, as it seems like only line drives are rewarded with good baseball outcomes.
2. A 45 degree trajectory achieves slightly more than twice the height of a 30 degree trajectory. This is not a small matter, as everyone who has looked at the subject says that Safeco is subject to unfavorable hitting winds blowing in from the outfield, and plays much more lively when the roof is closed. The balls that stay close to the ground are more sheltered from the wind than the ones with some height to them.
To see this play out, here is the highest trajectory home run hit in Safeco in 2014, compared with a typical 30 degree shot.
| MPH off bat | trajectory | Apex | ||||
| 6/14/2014 | Video | View | Chirinos, Robinson | 100.7 | 30 | 82 |
| 4/23/2014 | Video | View | Carter, Chris | 102.4 | 38.1 | 144 |
The Chris Carter bomb is 38.1 degrees, and travels at 62 feet higher than than the Robinson Chirinos shot. There is no 40+ degree home run to compare to the typical Chirinos shot, as all 45 degree shots at Safeco have been destroyed with prejudice and were not recorded by Hittracker. Also note that the Carter shot was along the left field foul lines, which is more sheltered from the wind by the upper decks of Safeco (where Doc sits). Maybe the Carter home run wouldn't have made it out of center field or right field. The roof was open for the Carter home run. Note that the Carter shot maybe wouldn't have made it out of dead center just on the merits of the field dimensions.
The average shot trajectory of a Safeco field homerun is 27.8 degrees, which is an extremely sharp angle compared to what I was expecting. Basically, launch angles of 20 to 36 degrees equal a good hit, and everything over 36 degrees is suspect. 40 degree fly balls are cans of corn at Safeco but will defeat some parks.
Comments
I can tell you that all analysis of hit f/x data done by teams makes use of launch angle - and I can tell you that park factors will evolve the minute someone realizes that breaking hits up by launch angle, RPM and launch velocity and then calculating the mean "delta" between actual travel distance and expected travel distance in a neutral sea-level spot will give the best mean "weather f/x" that money can buy.
In your spare time, you might be able to develop this theory into a true Thesis into a real career Matt... we are waiting.
You're exactly right, Moe, that this sort of conversation is astonishing. The last two posts and the commentary following are just incredible. Good work everybody and thanks for kepping hte door open, Doc.
You're exactly right, Moe, that this sort of conversation is astonishing. The last two posts and the commentary following are just incredible. Good work everybody and thanks for kepping the door open, Doc.
Or I'd be doing that now. That's the problem I face...I simply do not have access to that data...HRs aren't enough because, as noted here, they select out a ton of launch angles and hang times.
His problem could very well be launch angle. As you noted, you only caught the balls he nutted. Not the warning track outs.
Moe: Could you do a post on ballooning a ball from a sub optimal launch angle? As I understand the process, its when a ball rises from backspin from an already high launch angle, and this causes the ball to stall out and lose momentum. Like you think, I'm sure this happens at Safeco, because I've seen lots of hits stall out on the warning track.
Other golf/baseball stuff: Baseball and golf have opposite goals. In baseball, the goal is to make the ball on the field as squirrely and unpredictable as possible. In golf, a topped ball with backspin is the best because your ball stays where it lands instead of bouncing. To that end, I think that James Jones and Robinson Cano have developed a nasty habit of slicing the ball down the left field line, and this leads to doubles and triples. Seager has a hook problem with regard to the right field line. How do you create a slice or a hook with a bat, as these curved balls are some of my favorite hits?
Also, what about Ackley? I read somewhere that he was near a pro class golf player. Maybe his fine golf swing has confounded his baseball swing and has been booked by the opposing defense?
Matt, I'm sure that the low launch angles, 0-20 achieve good results in baseball, but what about the high ones? If you've used Hit F/X in the past, is there any situation where a launch angle of 40+ degrees results in a good hit, other than the fluke home run?
Also, I knew you've been holding out on us regarding some good hit F/X stuff that we want to know about. Hit F/X seems like it would make stats like home run percentage per fly balls and babip seem kind of weak. It would be replaced by things like Batting average on launch angle of 10-20 degree at velocity greater than 90 miles per hour, and stuff like that. The whole babip fluke debate would go up in smoke. In short, it would be pretty easy to separate good ball trajectories and speeds from bad ones.
Too high of a launch is not good in and of itself. When you add too much backspin and you get the ballooning effect.
From golf-simulators.com: With really high spin rates the magnus lifting effect will actually increase the ball's rate of climb.
The modern driver has a much lower center of gravity than the old wooden one. Lower center of gravity means higher laund angle. To compensate for that modern drivers are generally less lofted than onld wooden drivers. The old driver had commonly 13* of loft. The modern diriver is between 9-11*. Because the modern drive is longer and lighter you get greater club head speed and generally more spin. Higher launch angle and more spin is a bad marriage for a driver, unless your a low speed amateur.. To compensate the modern ball is designed to actually spin less the harder you hit it (to some degree). By th way, that means the newer ball flies straigher, too..
A study somebody did (before the fences were moved) indicated it most often was counter-clockwise with the flow toward home plate from left field. Of course this is not a constant, just the prevailing flow, which is dependent on outside air flow too. A significant contributor is the park construction configuration, which is logical, as is air temperature and density.
I am not allowed ot discuss anything I saw while working for the Yankees until one year after my date of termination in specifics...and I don't think I can talk about specific methods in enough detail to replicate them ever. But I can say that they had ways of looking at all of the available hit f/x data using the relationships between those variables and each other and between those variables and runs created resulting from each batted ball in the aggregate. Meaning they looked at launch angles, velocities, spin rate, launch azimuths...not to mention things like time to first base. So yes...they have moved beyond BABIP...well beyond.
I don't actually know how the vertical launch angles break down in terms of run values, but my guess is that the optimal angles are exactly what you've found for distance generation and that if you go higher, it's easy to get under the ball and field it.