Yep, that's exactly what I'm insinuating. Methinks these broker desks which ultimately are subgroups within the futures brokerage, can dish out flow to whoever they want to use. If who they are using a proprietary market makers then in fact you are trading against their book and if they can arb your flow, so be it. I'm not sure if that really happens. Probably would be illegal- I think it's more like there is an unspoken camraderie with executing brokers and locals. Like Johny X at FCM knows a certain local in the corn pit and knows that when an order from x account comes in, he'll be his go to guy. I would LOVE to actually know how orders in option spreads are displayed to the "market" or to the pit to insure competitive pricing.
As far as trading goes, I tried doing a blackbox automated rules based system using Qcharts, Button Trader and Interactive Brokers that was based on Demark Sequential countdowns. Bottom line, system connectivity and IB's glitchy interface didn't make it a reliable system and my rules based model didn't really pan out. Other than that I'm mostly an options guy in commodities. Cattle, Corn, Gold, Euro, Bonds. I trade mostly for the intellectual satisfaction and in excercising trade discipline. In my earlier times I blew up several accts at Alaron, Refco and Rosenthal trading way too big and undisciplined. Made massively big and wrong bets in Eurodollar spreads, got way too long in Gold into a blow off top, Got short the Euro on its way to parity with the USD back in the day etc. Interestingly, most "blow up" trades ranged in losses from 6-12k .