[dickiegera]

I finally had a hand that surround play came to be.

Declarer LHO was in 1NT and after 5 or 6 cards had been played I found myself on lead with Q1083 of diamonds.
Dummy had 942 and I led the 10. I recognized surround play. LHO held K75 partner AJ6.
Declarer played the king and partner won with Ace.
However partner did not return diamond.

Question how is partner to judge the situation?
My lead of high card in diamonds was inferred by partner to mean I had no interest in diamonds.

AGAIN HOW WAS PARTNER TO READ THE SITUATION.

WE talked it and came up with no good answer.

Help would be welcomed.
Thank you

[kuhchung]

teach him the surrounding play

[lexlogan]

The Ten is an honor (AKQJ10 are called honors), not a spot card. You generally do not lead an honor unless it is a singleton, doubleton, or top of a sequence. Seeing you led an honor with the next lower card in dummy and the one below that not visible, partner should consider whether the surround play is plausible (i.e., could you have the appropriate length.) I see many players who mistake 987xx for "top of a sequence" (a sequence must begin with an honor) and others who, like your partner, mistake the ten for a "spot" card. At least your partner recognizes that the card you return says something about your attitude toward that suit!

[WesleyC]

To summarize lexlogan's reply more succinctly:

If partner plays the ♦T with ♦9xx in dummy it almost always shows ♦HT8 because leading the ten from any other holding can easily blow a trick.

(The only alternative is a desperation lead, hoping to cash out 3 diamonds immediately if partner has precisely ♦AQJx.)