Another question already asked about weapon damage per second (DPS; damage per hit and 'reload time'). The accepted answer basically states that "they are different in terms of reload time, however, they are not different in terms of damage done per hit."
I'm curious about how melee weapons compare to each other in terms of swing arc and reach, as this is another significant factor in melee weapon choice, aside from 'reload time'. Is there a ranking of melee weapons in terms of swing arc or reach?
The Left 4 Dead Wiki doesn't seem to go into detail about this part of the melee weapons' stats.
Best Answer
A lot of the information you're after is already covered on the other question/answer so I'm not going to duplicate it here. In regards to which melee weapons have the largest swing arcs and which reach the furthest, the obvious choice for both is going to be the Katana with the worst being the Nightstick.
Weapons with a large arc allow you to hit multiple infected with a single swing, weapons with a larger reach allows you to hit multiple enemies deep with a single swing. This means if you have a zombie behind a zombie and hit the front zombie with a Katana at very close range, you'll also hit the zombie behind the front zombie, in addition to any zombies to the immediate left and right of the front zombie.
Large arcs and furthest reach;
The remaining melee weapons are all shorter range with smaller arcs;
As discussed in the other answer the damage per hit of each weapon is the same, with the exception of the chainsaw. The main difference between the weapons is attack speed, which is detailed in the other answer as well.