I would like to reiterate what Gleff said concerning needing to book 330 days out.

I have burned through about five million miles travelling on all major US and many of the major international carriers, all at saver levels, some coach and some premium awards, and have never booked more than 8 months out. Travel has often been during peak travel periods and all these redemptions have been in the last three years.

I do all my booking myself, know/research my options very well, am usually told no go until I get an agent to check the specific flights I found on my own already - using an availability tool or multiple airline websites.

As Gleff said, diversifying is essential! I maintain miles in all three alliances, trying to build the easier to redeem balances the most. In my experience, OneWorld is best, and Star next, with SkyTeam the hardest to get peak redemptions on.