One thing why TF2 can't be normally bhopped. Its still same engine, but TF2 is slightly modified. Normally, CS engine is kinda "fully accessable" by default. You can edit any variable you want. But TF2, since its F2P and more popular, to be more safe from console hackers, has engine modified, so some essential physics can't be modified by default. You can bypass this by using SourceMod on your server. So, thing why CS is Bhoppable is, that cvar sv_airacceleration is set to 150 by default. That's why you're able to get speed with strafe. In TF2 is this cvar hidden, and its set to 1 i think. Thats why you simply can't get speed with strafing. You can Bhop if u mean just jumping, but not, if u wanna get speed with it. But for example on jump/surf servers is sv_airaccel + sv_accel + sv_wateraccel modified, so you're able to get speed with bhop, or keep movement speed with bhop. And if u want that bhop script, i had one topic with mine on theese phorums. It will keep you jumping everytime u touch the floor. Works everytime on jump/surf servers, but on some servers without support of wait command it can cause lag (have i found magical "upward force cancellation??
"). So please, use it on jump/surf servers to dont lag your game