Posted 2012-February-23, 08:58
There looks to be a very good chance of N making more than 8 tricks in the absence of the revoke. The only lines I will consider are ones where E plays a diamond at trick 4 - E doesn't get the benefit of changing his play from that point, but declarer can now just draws trumps and wait to be put back in to take his diamonds.
The law talks about assigning an adjusted score at 64C, so I think you can make a weighted adjustment, rather than just fixing on, say, 9 tricks. Yes, if E held a club honour that would in principle make a difference. If his cards were completely different altogether, that would make a difference too, so a small change must also matter.
I'll leave you to estimate the probabilities of various lines, like W gambling by leading away from the CA when put in with the 4th round of trumps.