Conditions: Coral Sea scenario, all Japanese a/c stood down except 27xNell in Rabaul set to search 30% (8 a/c total searching), 6000 ft, 14 hexes. Experience/search skill around mid-50s.
The Nells are looking for the 4 US TFs, all 14 hexes from Rabaul (see picture). They are the default ones from Coral Sea scenario. The TFs are relatively small; 2 have a CV and a few CAs/DDs each; 2 have an AO and DD (or maybe ~two AO each + DD(s)). Anyway, somewhat hard targets to spot.
Comparison of 3 cases, 7 samples each:
1. 7 samples of Nells with no search arcs set (0-360).
2. 7 samples of Nells set to search "optimal" search arc, covering exactly the 40 degrees the US TFs are aligned along at 14 hexes. This is about as good a search as you could do if you knew exactly where the enemy was (apart from sending more planes!).
3. 7 samples of Nells set to *opposite* search arcs (looking north in exactly the wrong direction, around 340-020 deg).
Results (number of TFs spoted per sample):
No search arcs: (1/1/1/2/1/2/0) (mean = 1.14 TFs spotted)
"Optimal" search arc: (0/2/1/1/1/2/0) (mean = 1 TF spotted)
Wrong (opposite) search arc: (0/0/1/0/0/0/0) (mean = 0.14 TF spotted)
I ran two 2 sample t-tests in SYSTAT to compare cases (1. & 2.), and (1. & 3.)
No search arcs (1) vs. Optimal search arc (2). p = 0.73. (no significance)
Optimal search arc vs. wrong search arc. p < 0.006 (quite significant difference).
Discussion:
I don't claim this covers all cases, and there are confounding effects like weather which I didn't examine. Maybe in some cases you do get better results by setting the right search arcs (longer/shorter search distance/altitude/larger TFs, etc.). And although the mean is slightly lower, I certainly can't claim that setting the right search arc is better or worse than setting none at all. But I do think this demonstrates that setting the *wrong* search arc is worse than setting the right one OR setting none at all. So in this type of situation you probably aren't much worse off setting no search arc than setting the right one. Which, of course, you can't perfectly predict.
Conclusion: On average (assuming the enemy sometimes comes from directions you don't set as arcs), you will find him more often *under similar conditions to this test*, if you don't set arcs. I think I'm going to take off all my search arcs.
