Conkers are the nuts of the Horse Chestnut — not the one you eat, the other one with the really spiky outer covering. It is a regular autumn pass-time in England for school-boys to put conkers on the end of bits of string, and commence doing battle.
The game of conkers is played by two players, almost always by challenge. One player holds his conker up at arms length on the end of its bit of string, and the other player tries to swing his one with sufficient force to break the other player’s conker. After a swing, roles are reversed. Since this is a virtually solely male sport, whose participants’ average age is about seven (although there is a bunch of nutters who regularly get on local news programmes with their “world championship”), there is of course much potential for strategic ‘misses’ against the opponents knuckles, or indeed against almost any other part of his anatomy.
In the (rather unlikely, usually) event of one conker breaking the other one, the winning conker becomes a ‘one-er’. A conker which has won twice, is a ‘two-er’. Hence a ‘sixer’ (although it must be remembered that there are of course the usual collection of bogus seventeeners and sixty-seveners which circulate the black market of the playing field). There is a black art as to how to ensure that your conker becomes a sixer — baking very slowly in the oven overnight, is one approach, as is soaking for a week in vinegar. Most of these methods tend to make the conkers, if anything, more rather than less brittle. There’s probably a lesson for us all in there somewhere.