Granted that this has been against 3 AI games and a hotseat game with my son, but my personal experience with sub ops has been the following.
As the allies, I train my Air assets until the average pilot ASW experience is in the 50's. Especially the restricted command bombers on the US west coast and then all of the float plane groups that start arriving. And I assign commanders with high Nav and aggression ratings to these air groups. For my ASW TF's I don't bother using the YP's. They just have ASW ratings of 1 and are floating coffins for their crews. Instead, I convert them to ACM's and stick em in my major ports to maintain the minefields. Minefields are a wonderful ASW platform. For my other ASW assets, as the SC's and other dedicated ASW ships arrive I change their commanders, to commanders with the best available Nav and Aggression ratings I can and then stick them in TF's with the highest aggression and leadership rated available TF Leader possible.
Keep in mind that for air groups that are smaller than size 10 they can either do ASW or Search effectively or both along a very narrow arc. I prefer to dedicate my smaller groups to search only. Along the U.S. West Coast, I have a Kingfisher group at every coastal base. Either I parked an AV/D/P at the port or I moved one of the inland base forces to the coastal base. I have approximately 16 Air units along the US/Canadian coast with overlapping ASW arcs completely blanketing the coast.
For my ASW groups, I set them on patrol zones between 1-3 bases with transit paths that are no more than 6 hexes in length between Patrol points. I set them for 1 day delays at each patrol point. As of January 1943 I have approximately 10-15 of these HK groups consisting of AM/SC class ships on overlapping patrol patterns. I don't just park them at a single port, but every port has at least 1 group in it nearly every day, especially San Francisco and Los Angeles.
So far in my game with my son, I've lost maybe half a dozen AM and SC's and a handful of merchants in return I've sunk about 10 I-boats. I get at least 1 sub prosecution from my ASWTF's or my Airborne ASW every turn. Most of the time I don't actually hit the subs, I see a lot of "Sub spotted", "Sub evaded contact" messages, but when I do prosecute contacts I am damaging the subs as often as not. My son has complained that he subs spend more time getting repaired than they do shooting at my ships. A result I am more than happy with.
For Convoy escorts, I generally try to stick with the longer range YMS/AM/SC ships. Again, I replace crappy leaders with the best available ones, especially those with higher aggression ratings. Generally I will put at least 6-10 of the small escorts into every convoy and I don't leave unescorted merchant ships sitting in TF's. I've found one of the real threats with the AI is that it is incredibly aggressive with the midget subs and I had the Lexington take a fish 2x now in one of my AI games from midget subs.
As far as allied submarine warfare. I let the computer handle the long range fleet boats. I just stick em in single ship TF's put em on max react range and let em go. Whenever I see one was attacked by ASW or Air assets, I go check on it and move it if necessary, or if its been damaged, I send it back to port if its sys damage is 10 or higher. The Japanese AI has been very aggressive using ASW TF's but not so good at escorting its own convoys. I find that when my subs have been spotted by Aircraft is when they are most vulnerable. I keep control of the S, dutch and British boats myself and use them in known choke points using patrol zones. I found them to be incredibly effective early in defense of Java as I literally saturated the coasts around Palembang, Batavia and Soerbaja with these subs.
Even early in the war, both against the AI and my son, I was averaging at least 1 sub attack a day, the more aggressive commanders would surface and use their deck guns as often as not, especially early with the dud torps on the Fleet Boats. Now that its 1943, my subs are suddenly the terror of the South China Sea, but even in 1942 I was killing a merchant ship about every 3 days with the Fleet Boats. Now its obscene how effective my subs are. With the lower dud rate, I'm killing at least 1.5 Japanese ships a day, even in escorted convoys, especially against the AI. My son has had a bit better success against my subs by using many of the same tactics that I do, particularly with Airborne ASW. He indicated that once he started training his patrol aircraft to get their ASW ratings into the 50's his ship losses have mitigated and effective attacks have gone up significantly.
Anyway that's been my experience. Not every game has been exactly the same, the AI particularly, seems to have a large variability.
This is an excellent summary, and should be read by every beginning player. I especially like your use of the Kingfishers along the coast. The Allied player gets a bunch of these groups very early, and they are great for spotting. I've gradually learned to not expect the airborne assets to attack and hit anything. They are just "reaction engines" for the ASW TFs, which do in fact react like crazy if you let them off the leash. I also echo your thoughts on YPs. Pretty much a waste of time. OTOH, the Canadian KVs have been great little assets.
< Message edited by Bullwinkle58 -- 1/7/2010 12:52:14 AM >