[Lori]

In my opinion you shouldn't have had the fifth part of the bet if you were not sure what to do should the first four win.

If you think the -3 part of the bet has any EV at all, then you are right to middle. However with you thinking the +3.5 is +EV then I would assume it is unlikely that the -3 would be too.

At this point it would become more of a hedge than a middle (The middle being the +EV bet).

However if the -3 is EV neutral then you could back it as big as you liked to make your returns more comfortable, and if it is SLIGHTLY negative then you could take it too because having a slightly bigger bankroll guaranteed will have some future value to a winning player.

Of course, if you end up taking a slightly negative bet, you only have yourself to blame for getting into the position where taking it might be correct, however just because you shouldn't be in that position doesn't mean it is neccessarily wrong to take it.

The fact that this is a middle and you could win both ways is always a nice thing, but in EV terms is totally irrelevant (That being said, I only usually hedge on bets where I can have a slight middle as it is always nice to have a big parlay come in and is therefore nice to keep it live with an middly-hedge )

I am also 99% certain you already knew all of the above, but maybe it will help you make a choice.

Lori