I have a smart "router" that takes into account liquidity, market spreads, execution cost, current market conditions, etc.....It is call my experiance. I've been working on it for a long time. I trust it to do it's best. When I makes sub optimal decisions, I learn and move on. I only expect my trading platfrom and broker to offer me the opportunity to have access with software that is easy to use-for me. I know, I'm old school, but comfortable with technology and with an understanding of market structure that helps me just focus on the end results and not all the noise.