I'd be surprised if the frequency of the On-top numbers didn't mirror the post positions rank.
I'll check the Exactas to be sure.
My problem has always been finding the underneath number, the one that spoils the ticket
My posts here on the Dime supers (1 on-top 5) haven't shown it but I've had good success by constructing the ticket with My Pick on top of the next 2 picks plus best post (if not used as yet on the ticket) and lowest inside post not yet on the ticket.
Here's my run for today, we'll see what happens.
Dayton R2........ 4 / 7,5,9,1,2
Dayton R4........ 4 / 5,2,9,1,3
Dayton R5........ 5 / 6,3,9,2,1
Dayton R6........ 8 / 4,9,5,2,1
Dayton R8........ 1 / 5,9,8,4,6
Dayton R10....... 8 / 4,9,5,2,1
Monticello R7.... 1 / 2,5,7,6,3
Monticello R8.... 6 / 1,2,4,3,5
Northfield R5.... 8 / 1,5,3,2,4
Northfield R10... 7 / 2,1,6,3,4
Batavia R2....... 8 / 1,5,4,3,2
Pompano R3....... 9 / 6,5,2,3,1
Pompano R8....... 6 / 4,5,8,10,2
NFLD, BTVA, and PPK are 20¢ tickets