maybe my question really should be how can we increase his chances of getting in?
Sadly the answer to this is probably to move within the 12.5 mile radius!
Seriously, until next years results come out no one really knows what approximate pass mark will be required for out of area admission but I think it is safe to say it will be pretty high. Kegs has traditionally required the highest pass mark of the boys grammar schools in Essex and whilst the new catchment area may slightly lower the mark required for in area admission most people think out of area will increase significantly as there will be so few places available.
As you are out of area are you considering any of the other grammar schools as well?