My understanding of heavy cavalry in this time period is that its effectiveness revolved around using the sheer mass and momentum of the charging horses to crash through and shatter enemy infantry formations.

What happened when 1000 mounted knights squared off against 1000 mounted enemy knights though? Would they just couch their lances and ride directly into each other in close formation?

There doesn't really seem to be much discussion of this that I can find online, so I am curious if anyone knows how a situation like this would actually play out.