> ..., did this include kicking the table slightly with your foot to break your opponent's concentration or something to that effect?

We would not have considered such tactics as allowed by the rules, and not effective at 5min/game sudden-death time controls anyway. Rearranging the captured pieces while the opponent was thinking at longer TC was fun, however. especially when you were ahead. Then you could nicely line them up so that the extra captured Pawn stood out. I put that on top of the clock once. :-) But let me tell you an anecdote about speed Chess. The open club championship attracted IMs and GMs, because they did have a money prizes in the first group. In the qualifiers my brother had to play a now well-known Dutch Chess player (now IM) who had come to collect that money, but had to beat my brother to qualify for the group where it could be earned. The game wasn't going well for him, though: it seemed a dead draw. The IM was fast, but so is my brother, so a win on time was by no means guaranteed for him. So the IM tries to gain time by shoving the clock away from the board each time he presses it, so my brother had to reach further to press it, losing time. As it became clear this alone would not do it, he pushed the clock (after starting my brother's time running, of course) so far that it fell off the table, and then kicked it with his foot sideways, making it slide two tables away. So that my brother had to crawl under the table to retrieve it first, before he could stop his clock after his move. This of course was a fatal mistake, because, while under the table, my brother was fully out of view to anyone. So when he finally surfaced, much to the dismay of the IM, my brother had not lost 15 valuable seconds as planned, but instead had gained 2 minutes, while the IM's clock was suddenly perilously close to running out. (The clocks had adjustment buttons on the back, after all...) Then the IM got very angry, crying foul. But of course he could not prove a thing, and had actully a hard time explaining to the referee how the clock could end up under the table in the first place. Of course everyone had seen (if not heard) how he had been abusing the $100-clock before, and this had not made him very popular with the organizers. So his protests were dismissed, and he forfeited on time, losing his ticket to the main group to my brother, and going home angrily.

Of course we mastered all the tricks, like moving your pieces closest to the clock when time would be decisive in a dead-drawn end-game like KRKR. If we were 'on the wrong end of the clock' we practiced 'the embush' in such situations. Which was moving back and forth your King between two squares very fast for a number of moves, enticing the opponent to do the same with his King (taking opposition) to not lose time. And then, when this had become an automated reflex with him, suddenly step forward with your King, so that when he mechanically performed the next sideway step, his King would remain attacked by yours. Then you could claim the game for him leaving his King in check. Of course that made them very angry, because they had counted on making you forfeit on time. But their protests, based on that you had stepped into check first, were always dismissed: they had not claimed the game because of that before pressing their clock, and that was decisive, according to the rules (which had just been changed to that effect that year). Of course after a few years they realized that the rules were broken, and changed them again.

> Even under time switching rules, the players can play to avoid situations where two consecutive switches are possible which might allow one player to switch and then wait nearly two hours before switching at the last second so his opponent loses on time.

I still don't see why you should be able to switch twice in a row for this. You just wait until your turn comes up. You could then already do this on a single switch. If you are the first to be able to switch, in such a way that he cannot immediately switch back, you just deplete his (future) time on 'thinking' about the move that will cause the switch. Basically the first opportunity to switch will be a win. I don't think you could do much to prevent white making a chain first: 1. d3 d5? {wait 1:59:58} 2. e3, game over...