Sorry I was kinda late with this, I've been arranging for houseguests.A terrible thing has been happening to me recently. I will shoot someone, they won't die, and I'll look at my netgraph and see something upsetting and yell
this server sucks and F10.
We all know that tickrate is important. But the setting is the goal. If your server cannot handle 66 ticks, and starts to drag down like this highlighted value shows, your server is going to suffer terrible problems. Bogus clientside blood because the player location warped a bit, interpolation buffers running out and making players jerk around, and all that fun crap.
Set your server to 50 or 33 ticks if your server starts doing this when firefights become large. Also, adjust the rate control values in your server config appropriately. (Default 66 tick: 66/50; 50 tick: 50/33; 33 tick: 33/20) Lowering player count can help, too, of course. You're better off with a stable 33 or 50, than a 66 that suddenly plummets to the 40's.
Note that the netgraph figure is based on client received packets, other things can modify this value, but if your connection is fine, a drop in this value indicates the server is unable to keep up with its tickrate.