CS2 grenade throw speed: 675, 438.75 or 202.5 u/s — nothing in between

How it was measured

Grenade release looks like it should be simple and is not. The demo records a projectile's positions, and reconstructing a launch velocity from positions has a built-in error: the first recorded sample lags the true spawn by a fraction of a tick, and at 320 u/s² of gravity that anchor error is worth several units per second on the vertical channel. A parabola fit on one real throw gave 217.9 where the true value was 221.9149.

The way out is that current demos latch the server's own launch velocity on the spawn tick. Read directly, stationary full throws cluster at mean 675.007 with a standard deviation of 0.09, independent of aim pitch. The horizontal channel is immune to the anchor problem anyway, because zero drag makes it exactly constant.

Weapon data explains only half of it. Every grenade in the game files carries a single throw velocity of 750 and no authored strength field at all, so 675 = 750 × 0.9 and the three fractions are code constants — later confirmed by transcribing the release function from the server binary, which reproduces all three speeds exactly.

The direction is where the community model was wrong. CS2 does not throw along the crosshair: it applies a piecewise pitch bias that is +10° upward when you aim level and tapers to zero at straight up and straight down. A linear approximation of that curve, fitted from demos, reconstructed throws to about 5.16 u/s of error; the native piecewise form reconstructs the same throws to a median of 0.00. The horizontal heading is untouched — launch yaw equals eye yaw with a median absolute deviation of 0.0001° over 535 throws.

The release law, as transcribed from the current CS2 server binary

s       = throwStrength                     // mouse2 / both / mouse1 = 0 / 0.5 / 1
factor  = 0.3 + 0.7 * s
if |s - 0.5| <= 0.1: factor = 0.65          // native midpoint snap
base    = clamp(750.0 * 0.9, 15.0, 750.0)   // 750 = vdata m_flThrowVelocity
speed   = base * factor                     // -> 202.5 / 438.75 / 675
pitch   = eyePitch - (90 - |eyePitch|) * 10/90    // native piecewise bias
fwd     = forward vector of (pitch, eyeYaw)       // yaw unchanged
src     = eyePos, with z lowered by 12 * (1 - s)
spawn   = trace(src -> src + 22*fwd, 2u hull).end - 6*fwd   // 16u unobstructed
initVel = speed * fwd + 1.25 * playerVelocity