I think Deep Finesse only tells you what is possible if noone gives gifts.  Clearly you did your part, but the other tables were giving gifts. 

deep finesse does "double dummy" declarer and defense. Which means looking at all 4 hands. You would think that knowing which way to finesse would result in more tricks for the offense than in real play. But my limited analysis shows that the average tricks on real contracts is more than the tricks shown by deep finesse. That is - that poor defense gives away more tricks than poor declarer play.

Is that the same as saying bridge is 50 (defense), 30 (declarer play),  20 (bidding)?  My numbers may be a little off but that is close to what I have read from several experts.

No I think it says a declarer sees both his hand and dummy so is less likely to blunder than a defender who sees only his own hand

in matchpoint play, bidding is 80% of the game. If you are in the wrong contract, it does not matter that you get an extra trick, u willl stilll get a poor result.

 

At IMPS, bidding vs play is 50/50.

 

In both, defense is twice more important than declarer play