This is an interesting thread.

I can understand the point of protecting if your live for a big payout in the last leg, given that these are pretty rare occasions where you simply don't have enough of these situations to let the "variance" even out itself over the long haul.

But speaking only for myself I would never let the results in the first few legs of something affect how I bet the next races/sequences. These situations are so common so I would think the "right" thing to do is to keep placing your best bets (the bets with the most expected value), and not "watering down" your value by buying yourself some false insurance in attempts to hedge. By doing this you are in effect playing against your own opinions (it was probably a reason why you left out those horses to begin with, in favour of including someone else), and at least if you know what you're doing that's not something one should do. In my opinion it's better to let the variance even this out in the long term, instead of "selling out at a bad price" for some insurance in the short term. I guess there is a reason why selling insurance is such a lucrative business!

But I would love to hear other opinions about this.