That seems to be the million dollar question. From my experience and if I had this number of holes to drill I would employ the most logical and economical plan I could. I would minimize travel between holes to reduce costs. That would mean starting at one side or end and working across to the other. If I started in the middle then worked out it would mean a lot of back tracking wouldn't it? Just a thought.

If I did start at one end and drilled 11 holes would I be to the sweet spot yet? Not likely but only my guess.

Waisting money back tracking and moving past drill targets to get to different drill targets wouldnt make sence to a lot of employers.