where does the saying in sport a "tin hat" come from

[impact5]

wheredoes the saing come from say in darts dont give him atin hat come from

[owdhamer]

In rugby league years ago there was a shout of give that 'ooker a piller any ideas

[FredPuli43]

owdhammer's is easier to guess than the first. The hooker is in the middle of the front three of the pack, obviously, and expected to pack down 'head to head' and shoulder to shoulder with the opposing front row, plus get the ball back. A useless hooker, once he gets his head down, might as well be given a pillow,so at least he's comfortable when he's asleep !

But a tin hat in darts? Unless it's a reference to not hitting the wire, requiring the man nearest to avoid the rebound, hence not giving the opponent the need for a tin hat, a helmet, to avoid being hurt ?

[impact5]

No i think a Tin Hat in any sport means winning without letting the other score
so it means giving a tin hat in any sport