Hey, I spend all week coddling and nurturing the infirm. I need to get out and swear like a sailor, grunt, crash and beat up my friends.
When I was growing up outside of San Francisco in the early '80’s I’d go to punk rock shows like the Dead Kennedys, DOA and the Subhumans. It’d be fun banging around in the pit. I realized that it was most fun if there was some guy there who was stirring up extra trouble. Not too violent, just rougher than my comfort zone. Someone to scare me a bit. Someone to make it hurt a bit. Someone to make it real. Now that I"m playing polo I realize that I am that someone.
I look at it as a public service. Because of me, my bicyclist opponents are developing better balance skills. 
Mallet construction: Maybe I’ll post pics later, but here’s a start.
Get a 52" ski pole. You can always cut it shorter later if you want.
Remove the grip and basket. You may want to cut off an inch or so off of the tip.
Cut a 6" length of 2 & 1/2" inside diameter PVC or ABS pipe.
Drill a hole in the middle of the side of the pipe just big enough for the ski pole to fit in snugly.
On the opposite side of the pipe drill a small hole just big enough to get a screw through. If you make these holes just a tad small, then the assembly with be tighter. You don’t want anything rattling around here. You can always use a rat tail file to increase the size of the hole a smidgen if you need to.
Go to the hardware store and buy a coupling nut and a screw that fits it. The screw should be about 2 & 1/2 to 3" long. A coupling nut is just like a regular nut except that it is really tall, about 1/2 to 3/4".
Drop the coupling nut down the ski pole until it gets caught inside the tip. You may need to experiment with different sized coupling nuts. The more of the ski pole tip that you cut off, the larger the inside diameter of the ski pole tip. That will necessitate a larger coupling nut, otherwise a smaller nut could fall through. Conversely, if you get a large coupling nut and don’t cut much of the ski pole tip off, then the nut will lodge too far away from the tip of the ski pole for the screw to reach it. Make sense?
Put the pipe onto the ski pole and insert the screw through the small hole of the pipe and into the tip of the ski pole so that it screws into the coupling nut. Tighten it up.
Drill lots of holes in the pipe to lighten it.
Cap the grip end of the ski pole with a nickle so that it won’t gouge anybody. Put on a golf club hand grip or make a grip on the ski pole out of an old inner tube and duct tape.
There you go. Have fun kicking bicyclist ass and beating up your friends. 
Geoff
Beyond that, I’d think the unicyclists would have the edge on maneuverability, though bikes might have the edge on speed if there’s enough room.
