Can someone please help me understand why points are divided by 3 in Pancakeswap masterchef's updateStakingPool method?

Smart Contracts
1 
function updateStakingPool() internal {
        uint256 length = poolInfo.length;
        uint256 points = 0;
        for (uint256 pid = 1; pid < length; ++pid) {
            points = points.add(poolInfo[pid].allocPoint);
        }
        if (points != 0) {
            points = points.div(3);
            totalAllocPoint = totalAllocPoint.sub(poolInfo[0].allocPoint).add(
                points
            );
            poolInfo[0].allocPoint = points; //setting first pool allocation points to total pool allocation/3
        }
    }