If supposed person was taller than you, and slower, it would be rule of thumb to go for their legs and capsize them. Once you have them immobilized you can do whatever you want with them. If they are small and fast you have to make every blow count, because you won't get very many chances before they overwhelm you.
If they are strong and fast, you'd better be able to defend yourself, and counter their blows and follow them up with your own.
A fight is more about concentration and stamina than it is about strength or speed. If you can run the gauntlet, and you are of at least medium strength, are otherwise healthy, and your environment can be used to your advantage then its more than 50/50 against someone of equal size or slightly more.
People I think I could take?
Give me a situation and I'll find a way out of it. Since I'm not a big or strong person I'd have to rely on my fox-like cleverness. I could talk my way out of a fight and intimidate someone with my words. If that doesn't work there has to be a way out. There always is. But don't get me wrong, if forced to, I would fight.
Although this is all hypothetical, and something unforseen could happen.
As far as tickling is concerned, well, when I visited my girlfriend I rolled her on her stomach, straddled her, and then tickled her sides. There wasn't anything she could do and there would have been no way out of it. The key is, you see, to keep a low center of gravity. Whenever the person you are on top of tries to roll you over, keep your body as close to their's as you can, and try to pin at least one of their arm. That should keep them where you want them.
Not that I know anything about it, I'm no tickle expert, but that worked for me.
