[rmnka447]

I put most of the blame with your partner for jumping to 6 ♥ over your 5 ♦ bid.

Your 5 ♦ bid has an inference that your partner missed even if you're playing 1 ♣ can show as few as 2 ♣. It would be natural for you to bid your ♣ control over 4 ♠ if you had one. So your failure to do so essentially denies the ♣ K. That means there is a real possibility of a loser in the ♣ suit even possibly 2 losers if you hold 3 or more. Tied in with the potential for a ♠ loser, bidding 6 ♥ is a big gamble. It essentially puts cards in your hand that partner has no way of knowing whether they are there or not. If you don't have the ♣ K, then you almost have to have the ♥ Q and the ♠ K for the slam to have a good chance to make. That's just not good bidding.

[WellSpyder]

bilalz, on 2018-April-13, 05:41, said:

In my partner's defense, this was at our local club where we have a good chance to score an extra trick or two (which he duly did) and he is a very good player.

That's not a defence for overbidding - quite the contrary. If you can make an extra trick you will score a top when playing in game anyway.

(I think with a few simplifying assumptions a match point analysis shows that you should bid a slam when the room has a 50% chance of making 12 tricks, regardless of your own chances of making 12 tricks.)