In the early stages of a debate, you may start to get an inkling that you're in for a hard time. Your opponent has started well; they seem eloquent and informed, and they're growing in confidence. If this happens, then you need to nip it in the bud before the situation gets out of control.
One strategy for doing this is to baffle them with science. This can be risky, as it's essentially a bluff, but it has been known to bring dangerous opponents who are building up momentum to a complete standstill.
The first part is this tactic to smother your opponent by citing complex statistics or obscure authorities.
If you don't know any suitable statistics or authorities, then you'll just have to make some up. With statistics, the key is to be precise. Always make up percentages to at least two decimal places. With authorities, the key is to name them well. Eastern European names like "Makrokovsky" or "Lavanovic" can be particularly effective.
The second part of the strategy is to shame your opponent into silence by making out that anyone with a double-digit IQ would know exactly what you're talking about. The last thing that you want is to be asked for detail about what you've just said.
If the worst happens, and you are challenged, then you're committed; the only thing for it is to back up your spurious authorities with more spurious authorities. Soon, the shame will kick in, and your opponent will slink away.