What's dead reckoning? Where can I find some turtorial?

A quick google brought me this page: Targeting A variation of dead reckoning. Or even this one on Gamasutra: Dead Reckoning: Latency Hiding for Networked Games. Oh, and here's what I typed into google: Google Search: dead reckoning programming. I don't know anything about it, so I won't be able to help you further. Hope these links help!

Dead reckoning is an algorithm which attempts to "hide" latency. If you simply send position data every x seconds, then this will result in players "hopping" every now and then. If you send data every millisecond, this will kill the server.

Thus, we need to be able to send data only when neccessary. Dead reckoning applies physics to move the player from point A to point B in a smooth way. It calculates the path by taking in such factors such as speed, velocity, etc.

This thread already answered the question. Please use the forum search before posting basic questions.

Or Use Google.