I dont think its Flippers going by what others have counted and not Slings , pop bumpers
I just roughly followed Swinks lead although I would be willing to argue a few things
that Jady left on the cutting room floor
don't argue, happy to agree and go from there 
, rather have a consistency. like every game has 2 slings and 2 flippers but if a game has a extra flipper yes add it as a feat5ure but maybe with a note (third flipper)
thoughts - it's still earlier days and each guy to go back and slightly edit.
Jady
I agree with the flippers, Pops and slings being left out
what I was waiting for was some one counting the Top magnets on Sega's SST and other Sega games that feed the in lanes, that feature is basically doing the job of a pop up post as on IM CSI etc.
