I am not proud of this but I had a good hand with trump support and wanted to show support beyond game. Scrolling through the GIB commands, I found the only way of doing this opposite partner's rebid of 2♥ was a splinter bid of 4♣ or 4♦. Robot partners so far had been quite patient about occasional lies, so I thought I might bid 4♣ now and if I hear 4♦ just hope for a ♣ control and head for a slam. Well, my 4♣ bid got doubled but I went on as planned with the deserved result of losing 8.14 IMPs because those players who just jumped from 2♥ to 6♥ made their slams after a ♠ lead!
OK, OK, I got the message: Next time I fake a splinter and get doubled, I will not assume my partner has a control . Anyway, this is not my point. My point is: Does it make sense to play splinter bids at all?
Let me add a few words to make this point more clear. In my home country's official bidding system a splinter in a simliar situation shows exactly 17 - 18 points. A splinter bid directly over a 1M opening bid shows exactly 14 - 15 points AND 4-card support of the 5-card major AND, of course, a singleton or void. As you can imagine, these hands come up less than once a year. Isn't that a waste of a wonderful bid? I mean, in the board above if a jump to 4♦ simply were a second-level cue bid with trump support and a slam-going hand, my partner would have KNOWN that a slam can be beaten by leading clubs, and we could have won 2 - 3 IMPs by peacefully playing 4♥ ...
(By the way, although successful here I don't believe that jumping to 6♥ is the winning action in the long run.)