My post over at Thoroughbred Champtions generated just the kind of discussion I was looking for, with over 75 awful names being suggested. Some of the ones that I think are particularly bad (possibly bad enough to have impacted auction prices prior to their racing careers):
Dirty Dish Mitch
The Love Master
What a Gaylord
Stinke Pant's (yes, they put the apostraphe in the wrong place)
Kirby's Glue Foot
Uno Tess Tee
Annie Dirt Bag
A Colt Named Sue
King of Scat
In case anyone is wondering whether I could just study how these horses performed relative to their auction fees, the answer is 'definitely not!'. Without even looking at the results, I can tell you what we'd find - they substantially outperformed expectations, and would appear to indicate that purchasing horses with lousy names is a great way to get a bargain. The problem is, that these were the horses that people were able to think of. In general, that means they probably had some success on the track...or at least made it to the track enough time that some people have heard of them. Using this kind of after the fact selection of horses for a study will ALWAYS show strong performance. You can see why by trying a more extreme example. Let's test whether giving a horse a name that starts with 'Z' makes them more likely to excel on the track. Offhand I can think of...Zenyatta, Zaftig, Zarkova, Z Fortune, Z Humor, Zanjero...WOW! Definitely name all your horses with 'Z' names! You can see what the problem is here.
It's possible that you could get reasonable results using the second study design (compare auction prices to sire's stud fees) I mentioned in my previous posts with the horses people thought of that had bad names, but even that might be impacted by the fact that people will tend to remember superior horses. Perhaps the horses on the list, in addition to generally being relatively fast, also tend to have good conformation (which presumably tends to go together with speed). If that's the case, then they likely would have sold for higher prices than their sire's stud fees would indicate...so the study would tend to show that horses with awful names are a bad deal.
In any case, I'll definitely get more reliable results if I select names in a more random fashion. I'll go through the full list of horses for sale at a two year old auction and select those with awful names. I'll then compare their auction prices to their sire's stud fees, and see if they tend to sell any worse than the average horse at the same sale. My selections will focus on those names that include explicit sexual references, punctuation and spelling mistakes, and anything else that would make a name really embarrassing...not just a little unappealling.