JERRY-DO YOU TAKE HEAT INTO ACCOUNT?

[high roller]

by Dick Powell
(ARTICLE EXCERPTED FROM BRIS / TSN)

Why are some day\'s races faster than others? On tracks that have similar maintenance performed on them, the variances from day to day can be staggering. The answer could be as simple as the weather.

Horses in races perform anaerobic exercise -- they go into oxygen debt -- and secrete lactic acid. The conditions of the air that they breathe can influence how far and fast they can run at full speed.

In harness racing, the fastest times are usually run when it is hazy, hot and humid. Races run during the day are generally faster than those run after the sun sets. A hot, summer afternoon of racing at the Meadowlands can yield times that are a full second faster than if they were run at night.

Hot weather leads to fast running times. At least within reason. If the temperature exceeds 100 degrees, the effects of heat stroke and dehydration can be severe. Plus, if the horse has had to spend six hours in a detention barn before the race in very hot weather, all bets are off.

Humidity also helps. The heavier the air, the more oxygen it contains and the equine athlete is able to delay the inevitable state of oxygen debt.

When harness races are run at night, times can slow down as the night\'s races progress. A race run at 8 p.m. can be faster than the same race run at 11 p.m. With the sun down and temperatures dropping, races tend to slow down.

Here\'s an exception that proves the rule. In 1988, Mack Lobell broke Nevele Pride\'s long-standing world record for a trotter on a half-mile track at Saratoga Raceway. The race didn\'t go off until 11:20 p.m. that night, but it was a brutal, sultry night in August when the post time temperature was still over 90 degrees. Normally a race run that late at night wouldn\'t be conducive to a world record, but the hot, steamy weather made it possible.

So if we wanted to go for a world record we would want the race to be run during the day when it is hot and humid.

Quarter Horse racing gives us some insight into other ideal conditions. Just like harness racing, daytime racing is faster than nighttime racing. Wind is critical and Quarter Horse past performances tell you if the race was run into a headwind, had a tailwind or a crosswind. And time of the day is also important.

In many of the big-money Quarter Horse races, qualifying trials are run in order to gain entry into the semifinals or finals with the winning times determining who advances. There have been many instances of top horses not advancing through the trials since the wind shifted against them or their trial was later in the afternoon. With as many as 15 qualifying heats, the least little change in the weather can spell doom to even the fastest horses.

With most of the races being run at a quarter-mile or less, air quality becomes less important. Heavy air is not a help at all at the shorter distances since it takes less oxygen to utilize in a very short period of time. In fact, thin air helps Quarter Horses run faster times. Races run at altitude, like in New Mexico or Colorado, can yield faster times than those run at sea level since the air is easier to run through and provides less resistance. Even though there is less oxygen in the air at higher altitudes, the fact that the races are so short means the horse barely goes into oxygen debt.

In the 1968 Summer Olympics, held at 8,000 feet above sea level in Mexico City, sprint races and jumping events were all at or near world-record performances with the thinner air providing less resistance. However, in races at 800 meters and longer, the winning times were inordinately slow. The presence of the thinner air did not make up for the fact that the air contained so little oxygen, and athletes who didn\'t train at high altitudes suffered.

So the thin air at high altitude results in the short races to be run faster and longer races to be run slower. Even at 350 yards, the weather conditions and changing temperatures affect the winning times, which are timed down to a thousandth of a second.

So what are we to learn from all this? For one, pay attention to the temperature notation in the charts. An unusually cool day in the summer might explain why many of the races were run slower than normal. An unusually warm day in spring or fall might explain why many of the races were run faster than normal.

Harness racing places the temperature at the start of the day\'s races right next to the track condition in the horse\'s past performances. They obviously think it\'s important, and it\'d be nice if Thoroughbred past performance lines included it as well. Why not go a step further and have the temperature for each race and not just at the start of the day\'s races?

Wind direction and speed would also be helpful, but it will obviously change during the day like it did at this year\'s Breeders' Cup. If we had the graphic of the track\'s layout with compass directions, we could then take information like \"winds from the NW at 15MPH\" and determine if it was a tailwind down the backstretch. The National Weather Service provides this information for the area in which the track is located and a track could have its own measuring equipment. Track and field has wind measuring devices to ensure that sprints and jumping events are not aided too much by a tailwind. It can\'t be that hard to do.

If you are at the track or watching on a simulcast monitor, note which way the flags are blowing in the infield and how strong the wind appears. Even if you are not able to figure out the effect of the wind on the running of the race, it might help you understand variances in final times.

*****

[Easy Goer]

Seems more than coincidental that this article would appear in todays BRIS journal. Anybody know this guy? Is this a reprint from years ago?

Anyway, as I said in an earlier post, drag is proportional to density times velocity squared. The gist of this article is more concerned with the density part of the equation rather than the velocity squared term of the wind. Density is proportional to pressure (altitude), temperature (day vs. night in this article), and molecular composition (humidity), which explains why the drag can be affected by changes in these parameters.

Note the flaw in this article where he says humid air is heavier. In fact, humidity is water vapor (H2O), whereas dry air is mainly nitrogen (N2) and oxygen (O2) gas. The diatomic molecules of N2 and O2 gas are much heavier than water vapor (gas), which only has a single oxygen atom. Hydrogen is the lightest atom and does not contribute much to the weight of the water molecule.

All of this is what led me to ask the question about precipitation, which is liquid or solid H2O (and no longer gaseous), and IS much more dense (heavier) than dry air. Seems to me like it should be much more noticeable than 30 degrees in temperature, or 50 points of humidity. Since Jerry asked who cares about this, I guess the answer may very well be that I am the only one...

[Silver Charm]

If a horse runs in 95 degree hot weather, which supposedly makes him run faster, and gets caught up in a hot pace, wouldn\'t the resulting speed figure be counterbalanced by the heated conditions.

Another words all of this sounds like a bunch of HOT AIR to me.

[TGJB]

First of all, very nice piece by Dick Powell, who happens to be a regular reader and occasional poster on this site, and who also has been involved in this industry in a number of different capacities, notably in the Albany-Saratoga area. The most significant thing about the piece, in figure making terms, is that there are a whole lot of different things that can affect \"track speed\"-- some of which may have nothing to do with the surface itself.

Easy, only someone who has not made figures could ask questions like the one you asked, and the one about taking temperature into account when making figures. I\'ve brought this kind of thing up before, concerning the assertion in Ragozin\'s book that \"Seriously underconsidered by Beyer and most other modern analysts is the LIKELY speed of the track today, based on weather-- especially precipitation-- and on the track superintendent\'s habitual day-to-day changes in grooming the track\".

Now, I\'ll leave other absurd aspects of that statement aside for now (\"habitual\" is a beauty), and just focus on the one that I brought up here a couple of weeks ago. Lets say you found that on average, the track runs 5 points faster on Saturday than on Friday. Even leaving aside that averages themselves are used because there is variability in the data, how would you apply this information? Would you do Friday using normal means (looking at how fast the horses run), then NOT use that method to do Saturday, instead just assuming the same variant plus 5? The method was good enough for Friday, but not Saturday?

The same thing applies to the other factors that determine track speed. It\'s a good idea to get all the information possible, so that you have as many pieces as possible for the puzzle. But ultimately you use the past histories of the horses to make your decisions about what figures to assign now, and if you know what you are doing, you make as few assumptions as possible.

What is important about Dick\'s piece, and the \"Changing Track Speed\" presentation in the archives, is that they illustrate that it is  a mistake to assume the track stays the same speed. Humidity and temperature are two of the factors that determine \"track speed\"-- but there are others, and there are lots of combinations of all of them. I\'ve posted here about them many times.