I always have issues with Dave's control placement.
I can live with awful hiding of things, but placement like 17 (how many knolls were there??), or 15 (the area NW of it was not mapped - again more knolls/everything) make things very random.
That said, 15 was still my problem - should have gone straight on bearing.
3 had a bigger depression East of it, not on map.
11 was not on white.
Not sure if 14 was on knoll (I think I saw a knoll lower that I checked) or on a not-drawn root stock.
The map is crap for small detail. (I know, I mapped parts of it).
While we're complaining about the map, haha.... the well that was used for a control on Intermediate and Short Advanced was ~50m off from where the map shows it.