IMHO, the purpose of a claim is to speed up play. One of my friends, an excellent player, doesn't consider online bridge 'real bridge' because of the unnecessary pauses that occur simply because people aren't paying attention, are looking at another website when it's their turn, etc. thus causing routine hands to take 20 percent longer to play. Shouldn't we encourage claiming (of course, not frivolous claims) whenver (1) it is correct, (2) it is clear to the players at the table, and (3) the declarer says enough to make his intent obvious? (In cases like Axx opposite KQx in notrump, I think saying NOTHING is enough. In a higher level game, merely having enough tricks to take the rest is enough, assuming you have already displayed enough competence to unblock when necessary.)
Andreas would bristle at some of my claims. On a hand that is going to be positively boring for all, I'll say in the claim chat 'Please refuse if the diamond king is offside' and claim the tricks for making (say) 10 tricks with the diamond finesse. In my experience, nobody has ever complained and the opponents happily concede when the diamond king is onside. If they refuse, I assume it's offside and claim 9 tricks. So far, nobody has ever gained an extra trick by refusing the claim when the card was onside. If it ever happens, I'll know enough to leave a table where an opponent uses such a sharp practice to gain a trick. I think most people are quite happy to not have to play out a boring hand. If I notice that the acceptance/rejection is taking a long time, I'll specify what tricks I am taking in the normal chat, and in what order I intend to take them if it matters.
Against strong opposition, I have even claimed on a double squeeze simply by pointing out the threats and who I think is guarding which threats, since defending even this hand is going to be boring to them if there is nothing they can do about being squeezed. Of course, I couldn't say all that in the little chat with the claim, so I have to say it in the normal chat. If I've had an aberation and am wrong about the threats, I happily concede the trick (assuming that I wouldn't have gotten it anyway with my line - with any ambiguity going to the opponents.) Clearly it has to be a situation where I don't have to guess the ending - it just wouldn't make sense to claim there (especially with my cards showing, the opponents can conspire to discard quite deceptively!)
Playing out such a hand might take 5-10 minutes as the opponents are trying to defend assuming that I don't have the cards to make the squeeze work. Simply pointing out that I have the hand to make the squeeze work saves that time and gets another hand dealt which gives them their turn to squeeze me! Much better for them.
I would never do this unless I thought the opponents were capable of seeing the line of play. Otherwise I run the risk of initimidating a newer player into conceding a claim he doesn't understand, and that's just plain wrong. They shouldn't concede but they might not want to look inferior. Unless I actually know the player from having played with/against them before, I won't assume anything about a player unless his chat or his own explanations of claims indicate a high level of bridge competence. Of course, I can always ask in the chat if I should claim my squeeze or play it out.
One could point out that having ones profile marked Expert or World Class should be sufficient - but we all know better. I'll assume that a self proclaimed Expert knows how to finesse but nothing more until I see evidence that he knows more. I
do not intend to bully someone into conceding a claim they don't understand even if they have the impudence to call themselves an Expert (in theory, someone who has had success in national events - that leaves me out!) By the way, do you think it would cause anybody to change their profile self-rating if a lot of people did claim based on plays that a national contender should be aware of?
You can be sure that if the opponents could play my cards on a claim, I would (1) not claim without all tops, (2) play about half as many hands, and (3) scurry back to the Microsoft Gaming Zone where I'm allowed to claim!
I'm well aware that people can abuse the claim feature in this fashion, claiming all the tricks when they need a 3-2 break, and then finessing for a jack when refused! Once again, I think they should mention 'refuse if no 3-2 break' and concede the trick if it's not there, or play a couple of rounds first. In my experience, most players that claim on a 3-2 break just don't know any better - and I've never actually had anybody play for 4-1 after being refused. they just end up losing the trick.
I tend to lead fourth best - as opposed to the best suit, the second best suit, or the third best suit for our side