Can someone explain why you’d call your own flag to prevent the opponent from filling in thier scoresheet?
“It is not necessary to have a complete scoresheet to win on time in a non-sudden death time control. Calling your own flag to prevent the opponent from filling in moves on an incomplete score sheet won’t help.”
This was related to the difference between USCF and FIDE rules.
Unlike FIDE, in USCF non-sudden-death, a reasonably complete scoresheet is required to win on time (so that the player can prove, using only his own scoresheet, that the time control had not been reached). So one thing you can do (when you are in time pressure and an opponent with time available is blitzing you to try to flag you) is call your flag when it drops and have the TD check the opponent’s scoresheet for completeness before the opponent can make any additions.
It works best when you KNOW the opponent has missed more than three move-pairs. Also, doing it in a sudden-death time control is not a good idea unless you are essentially resigning.
One interesting addition to the above: CCA has a rule that says you can’t miss more than two move-pairs for such a claim in its events. (It’s one of CCA’s rule variants that is posted at every tournament.)
You might want to check out rules 13C - 13C12. From 13C: "…provided that the claimant has mating material (14E) and a reasonably complete scoresheet (13C7)…
So if your time control is 40/90 and your opponent has only moves 1-32 completed on their scoresheet, calling your won flag prevents him from filling in the rest of his scoresheet to comply with 13C7 (…no more than three missing or incomplete move pairs) and using his scoresheet to claim a win due to your flag fall. With you calling your won flag and his incomplete scoresheet the game goes on to the next time control.
Just for the sake of completeness, and to avoid a possible dispute based on misunderstanding the rules, the requirement that the scoresheet be “reasonably complete” only applies to a time forfeit claim in a non-sudden death time control. The USCF Official Rules of Chess explicitly state that a scoresheet is not necessary to claim a win on time in a sudden death time control.
Apparently the CCA rule pre-dates the USCF rule. When the USCF adopted the CCA rule it changed the requirement from being no more than two missing move pairs to no more than three missing move pairs. Bill Goichberg decided not to change the CCA rule to match the USCF rule.