Thinking about Biden's debate strategy...
My guess is Trump tries to get Biden off his game, make him seem like a doddering old guy, get him a bit unhinged. Spew out falsehoods - either about Biden himself or in general.
Biden's best approach is to not engage. Toss in a few "do you believe this guy" comments if you want, but direct it at the audience/camera/moderator. Keep his responses short and to the point (PLEASE don't say "my time is up..."). Calm demeanor. Look and sound Presidential. Don't get taken down into the mud. "I'm not going to dignify that with a response... and I have a feeling I might be saying that a lot tonight." Bottom line ignore Trump's attempt to bait you.
Don't give the bully the reaction they want strategy is prolly his best strategy