The TRIP factor is affected dramatically as field size increases; I am speaking from both a race quality AND betting standpoint.
Look, I play more grass than dirt because A) field size is greater on average, and B) better mutual potential. All I am saying is that for our greatest race, there is a point of diminishing returns, from BOTH a racing and wagering viewpoint.
Just look at English racing; extremely large fields in wide straights that often break into 2 or three groups, run tactically. Just look at how our grass stakes racing has changed to mostly even-paced early and fast final fractions.
I have seen too many good to great horses never getting a chance to show their best, and often, it had little to do with figs.