Average Starts: Mean vs. Median

In general, medians tend to be a better predictor of the future than means (averages), since they're not as influenced by extreme outliers.  In many cases, the median value can even be a better predictor of the future mean than the mean itself.  While I don't think that's the case with average starts per horse, it's worth noting that the median horse in my database has only 12 starts in their career (compared to the mean of 16).  It's not surprising to see the median lower than the mean when looking at a metric that has an upper limit so far above the values for most members of the population.

Average Starts Per Horse By Crop

Well, this isn’t exactly what I expected to find.  I took a look at the average number of starts per horse in each crop.  I was expecting to see a gradual steady decline over the past 15 years.  However, it appears that there hasn’t been much decrease since the 2002 crop.

For the 2011 crop, keep in mind that this data was gathered mid-way through their five year old season, so they will likely end up with a similar number of starts to previous crops.

These results definitely make the very high average number of starts that I found for some of the ‘old time’ sires’ offspring even more impressive, since it appears that the game hasn’t changed quite as much as I’d imagined.

Durability of Offspring of Big Brown and Mr. Prospector

In response to my article on Horse Racing Nation about the durability of Unbridled's Song's offspring, people mentioned Mr. Prospector and Big Brown as two other sires whose offspring might be expected to show signs of unsoundness.  My data on both is limited, but I took a look anyway.

Mr. Prospector's offspring showed an average of ten career starts.  That certainly suggests some issues, but may also be due to very limited sample size (less than 100 horses) in my database.

Big Brown's offspring so far are averaging eleven career starts.  That sounds bad, but it's actually pretty average for two reasons:
1.  I believe his first crop is only six years old now.  So a very large percentage of his offspring who have raced have not yet finished their careers.
2.  Other sires who began their stud careers in the 2007-2009 time period are showing similar averages.  This may partly be due to the factor in #1 above, and also may reflect the tendency for horses to race less than they did even 10-20 years ago.

Unraced Sires

Just noticed another of my old posts, addressing the issue of unraced sires (particularly, sons of Storm Cat).  Coincidentally, I saw the following article on Bloodhorse today: http://www.bloodhorse.com/horse-racing/articles/215550/unraced-stellar-rain-gets-his-first-winner  I'm hopeful that I can do some research and provide some real analysis on the topic sometime soon.

Blood-Ex: Anybody know what happened

I had completely forgotten about this until I looked back at my last few posts from 2008.  Does anyone know what happened with Blood-Ex?  I seem to vaguely remember them announcing some delays to their launch.  They definitely don't seem to exist currently, and a quick Google search didn't shed any light on what happened.  Does anyone know?

Reviving ThoroughMetrics...Again

I've finally gotten access to a good enough database of pedigree information and racing results that I should be able to do a lot of the analysis I talked about years ago.  As I work through the data analysis, I'll be posting here somewhat regularly, discussing some of the more interesting findings and issues I run into.  I'm also going to be publishing a series of articles at Horse Racing Nation, looking at a variety of questions related to thoroughbred pedigrees.