# 45 Strafe

Other languages:

45° Strafe is a technique that grants more speed than regular movement.

It can be done by strafing and turning 45° degrees (hence the name).

45° Strafe can be performed by either:

• Turning 45° left and Strafing right.
• Turning 45° right and Strafing left.

The turning must be quick (< 1tick) and precise (at least ±11.5°, the closer to ±0° the better), so it's difficult to perform consistently.

Some jumps require the use of 45° strafe, such as 1bm 4.375b.

## Effect on Movement

On every tick, the Player gains some acceleration depending on inputs and other factors.

• When moving forward (without strafing), the acceleration gained is scaled by $0.98$ • When strafing, the acceleration is scaled by $1.0$ Therefore, 45° Strafe is ${1.0 \over 0.98}$ times faster than regular movement (about 2% faster).

Special case: 45° Sneak

• When sneaking forward (without strafing), the acceleration gained is scaled by $0.98$ • When strafing while sneaking, the acceleration gained is scaled by $0.98 \sqrt{2}$ (≈ 1.386)

45° Sneak is used for no momentum jumps (example).

Outside of parkour, it's notably used for bridging, as it's ~41% faster than regular sneaking.

## Explanation

Below is a simplified version of the horizontal movement source code.

/*
* Code from Entity and EntityLivingBase
* Unnecessary or unrelated code is stripped out
*/

public void onLivingUpdate()
{
/*
* moveStrafing and moveForward represent relative movement.
* moveStrafing = 1.0 if moving left, -1.0 if moving right, else 0.0
* moveForward = 1.0 if moving forward, -1.0 if moving backward, else 0.0
*
* Furthermore, moveStrafing and moveForward *= 0.3 if the player is sneaking.
*/

this.moveStrafing *= 0.98F;
this.moveForward *= 0.98F;
}

public void moveEntityWithHeading(float strafe, float forward)
{
/* inertia determines how much speed is conserved onto the next tick */
float mult = 0.91F;
if (this.onGround)
{
/* Get slipperiness 1 block below the player */
mult *= getBlockSlipperinessAt(this.posX, this.getEntityBoundingBox().minY - 1, this.posZ);
}

/* acceleration = (0.6*0.91)^3 / (slipperiness*0.91)^3) */
float acceleration = 0.16277136F / (mult * mult * mult);

float movementFactor;
if (this.onGround)
movementFactor = this.landMovementFactor * acceleration;
/* base: 0.1; x1.3 if sprinting, affected by potion effects. */

else
movementFactor = this.airMovementFactor;
/* base: 0.02; x1.3 if sprinting */

this.updateMotionXZ(strafe, forward, movementFactor);
this.moveEntity(this.motionX, this.motionY, this.motionZ);

this.motionY -= 0.08D; /* gravity */
this.motionY *= 0.98D; /* drag */

this.motionX *= mult;
this.motionZ *= mult;
}

public void updateMotionXZ(float strafe, float forward, float movementFactor)
{
/*
* This function is responsible for the existence of 45° strafe. The geometry doesn't seem to make sense...
* Note that:
*     - Sprint multiplier is contained within "movementFactor"
*     - Sneak multiplier is contained within "strafe" and "forward"
* This is likely because Sneaking was implemented long before Sprinting
*/
float distance = strafe * strafe + forward * forward;

if (distance >= 1.0E-4F)
{
distance = MathHelper.sqrt_float(distance);

if (distance < 1.0F)
distance = 1.0F;

distance = movementFactor / distance;
strafe = strafe * distance;
forward = forward * distance;
float sinYaw = MathHelper.sin(this.rotationYaw * Math.PI / 180.0F);
float cosYaw = MathHelper.cos(this.rotationYaw * Math.PI / 180.0F);
this.motionX += strafe * cosYaw - forward * sinYaw;
this.motionZ += forward * cosYaw + strafe * sinYaw;
}
}