You know how I feel about the thought that drivers make horses go faster by magically yelling at them differently or whipping them harder, namely it is a quick way to go into the poorhouse. Perhaps it is an apt day (a day which Brian Sears won a ton of races at the Meadowlands) that I came across a snippet of a quote from Andy Serling on jockeys. For harness folks who don't know him, Serling caps for NYRA tracks. He is, in my opinion, the best thoroughbred handicapper in a public forum in North America for the runners.
In response to a capper who said "World class riders become world class riders because they make horses run who don't appear like they can run on paper", he said:
Not at all. The top riders are the ones that win with the highest percentage of their mounts that are supposed to win. That's all.
That is a sharp a statement on jockeys or drivers that you will ever see. I can see why his picks on the pre-game show have an ROI over 1.0, while many of his compatriots who tout driver/rider switches because they think that they make horses go faster are stuck in the 0.70's.