Grand Slam Wager

I saw kasept posted one of these in the selections section. I hadn't heard of the wager so had too look it up at the nyra website.

This is a multi race wager where you are selecting runners in the first 3 legs that only have to show. If the ticket is alive after the first 3 legs, your selection(s) in the last leg has to win. The payoffs listed at drf the last few weeks are generally in the $30-50 range but there were days when it paid over $200 and over $500. I'm guessing these were days when a few strong favorites ran off the board in the qualifying legs because the odds on the winner of the last leg on the $500 day looked to be 4-1.

Has anyone been betting this? It looks like a good deal if you can get some qualifiers who are not favorites in and hope the favorite is off the board. Is that a reasonable approach?

Doesn't look like I can bet this at TVG anyway but I'm curious what those who have played this think of the wager.