I realize no serious system builder would use Think or Swim's 'thinkBack' tool to develop a strategy... but I was playing around with it for fun and discovered the thing is so full of bugs many times it does not even calculate the profit/loss correctly on even a simple stock trade because it's not smart enough to consistently calculate splits and reverse splits. These issues render thinkBack untrustworthy and essentially unusable. Hopefully TOS will fix the bugs for future users.
When I tried using their tool over 3 years, it nearly drove me crazy with quirks and bugs. Moreover, it wasn't architected properly to be used as an automated trading platform.
Don't hold your breath .... http://www.elitetrader.com/et/index...while-multitasking.284770/page-2#post-3991356