He's referring to using it in a merge scenario, as he was replying to something you asked about why you would want to extend farther from a con.
That extension pitch back maneuver is used more in jet missile fights going 800mph where distances are greater and maneuvers are done over great distances. I feel like gunfighting is a little more straight forward.
Few tactics are limited to one specific scenario and the extension/pitchback has many uses. It's certainly possible to use it in a merge situation but it isn't limited to that. It does get a bad name from those that like to blow through and "extend" to 4 or 5k and then come back and blow through again five minutes later but that's not the extension/pitchback I'm talking about. Like I also said, a lot depends on the situation and what match up of aircraft you have. For instance, if you're in a slow, tight turner in a 1v1 you might want to be like the boxer that ties the other guy up and keeps him close so you can keep jabbing him. But, if you're the one with long reach (a fast, not quite as maneuverable fighter) or you're outnumbered, you might want to stay out from the middle of the fight, keep the bad men where you can easily see them so someone isn't punching you in the kidneys when you're not looking. Maybe then you would more likely work an extension/pitchback fight.
Also, no, the extension/pitchback fight isn't restricted to fighters with missiles or 800mph for that matter. Speed and range are relative things. It doesn't matter if one of you is at 150 and the other at 300 or if one is at 450 and the other is at 600 or if the fight is tighter than 1k or greater than 4k, it's all relative. The other situation, which really brought this up, is how to deal with two (or more) NME fighters on one. Many people will just stay there smack in the middle burning E trying to defend and take whatever shot they can only to die just when they think they've got a kill shot. However, you have a greater probability of surviving (and winning) when, instead of staying right in the middle of the fight you extend when you can to isolate the threat sector and get them in phase while maintaining or even building E. This is true even when you're the slow turn fighter against a couple of faster late war rides. You might not normally think about extensions in the slow angles fighter and sure, it can be difficult to gain any significant separation but it's not impossible and, if you can just reduce the threat sector from 360 degrees down to 180 degrees it's that much easier to keep track of the bad men and reduce the probability that you're going to be surprised.
Here's a nice little fight that starts out as a 2v4 then becomes a 1v2. It's the 1v2 that's interesting and I think it answers the questions on extensions from both Latrobe and Nath. I picked it because it's a classic NRG fighter(s) vs Angles fighter and there are a couple of examples of the extension/pitchback and how you can use it to isolate the threat and build a little E. It's also a great example where you can really look at the numbers to see what's really happening in the fight. I'll tell you up front that neither the 109 or 47 were overly aggressive and they stuck with the NRG gameplan throughout but to win that fight you have to keep the pressure on and bleed the other guy down so you can then convert your stored NRG into angles for the kill. It's possible that they just didn't feel all that aggressive that day but it's more probable that they were waiting for me to get slow before going for the kill.
BTW, just a personal recommendation but I like to view films first from the Fixed, Pan, Trails on settings in film viewer. It gives you the best overall picture of the relative positions and maneuvers. I also mention my speed on the deck in several places because it's a good snapshot of how I'm doing with my E. By looking at an aircraft's speed while it's flat on the deck there is no potential NRG (altitude) to consider, it's all kinetic (speed) so I don't have to do any messy math to compute NRG altitude in public.
httData Recovery Labs??????????????Data Recovery Labs??????????????Data Recovery Labs??????????????Data Recovery Labs??????????????Data Recovery Labs??????????????Data Recovery Labs??????????????Data Recovery Labs??????????????Data Recovery Labs??????????????žú| žú| 276626078MltCpy2.10 FILL FILLed Sector; ST500DM002-9YN14 (CC4H) S1D5GMZY Data Recovery Labs??????????????Data Recovery Labs??????????????Data Recovery Labs??????????????Data Recovery Labs??????????????Data Recovery Labs??????????????3mph. 200 to 220 is also my minimum target speed in a Brewster. It's a bit above corner giving me a buffer so I'll always have my best break turn available and the Brew also has a fairly decent vertical move at that speed so with 210 I'm feeling pretty comfortable. Of course some more E couldn't hurt.
Notice that I also have the NME in the same piece of sky for the next pass but there's some separation between them (a lead/trail formation) which complicates things a little. If I attack the lead then I'm turning in front of the trailer so that's out. If I pull up into the trailer the lead might have time to get his nose back at me. I choose to prosecute the trailer and, if the 109 comes around I'll switch over the top to the 109 but here's where the 109 helps out and extends rather than turn. I think that the Jug was thinking he'd stay high and when I turned after the 109 he'd roll in but I let the 109 pass me by and went after him instead. The 109's extension takes him out of the fight for about 17 seconds giving me plenty of time to attack the Jug. Unfortunately, my gunnery sucked :-).
As I defend against the 109 attack at 1:49 notice that on the deck I've now built to 235mph so I've added 58mph and have plenty of E to do an easy BRD against the 109 but I see the Jug is now headed back my way so rather than follow the 109 I drop back down to neutralize the 47 by taking him 180 degrees out. At the next merge they alternate for a few attacks but I've got plenty of E to evade afterwhich I quickly store some more E at time 2:40 as both of their noses are off but I make a potentially fatal mistake. Rather than turn my tail to the bandits and extend and climb away from them I half axx it and point too close to the Jug getting myself bracketed with one attacking from each side at 2:50 but at 2:57 after a break turn at the pass with the Jug I now have them both in the same piece of sky at the same range and in phase. This let's one defensive maneuver (a slice) defeat both attacks and the merge ends with both of them headed one way and me the other with good speed to gain separation.
Now look at the relative positions at time 3:09. This is precisely the picture you want to work for in this type of fight. Both NME still have 90 degrees to go before they can get their noses back on me and I've gone from 0 to 2k separation and from on the deck to almost 2k and this is in a slowpoke little Brewster. At 3:13 their noses are coming back on me so that will be the most separation that I'll be able to build so time for the pitchback. Actually, it's another slice since I'm climbing away at only 188mph but it's the same concept. Extend and then do your best turn to point back.
At this time, notice my speed on the deck at 3+26. 254mph. I've added 77mph over a three and a half minute fight against two adversaries. At the same time look at the NME's airspeeds on the deck. The 109 is 278mph and the Jug is 262mph. Anyone remember their airspeeds when they first attacked and I ended up down at 177mph? The 109 was 275mph and the Jug was 295mph . So, the 109 has stayed fairly NRG neutral throughout the fight while the Jug has lost about 33mph. Basically, they've stayed pretty consistent because neither of them were willing to really commit to a knife fight which would have required them to slow down but during that same period of time I've been gaining E by a few short extensions away from an isolated threat.
At time 3:37 what happens? They give me almost the exact same picture they did before with the 109 passing first and extending while the Jug turns. This time my gunnery is much better and the Jug goes down and then shortly after the 109 finds his way back to the fight. He dives in, I do a BRD with a rudder roll at the top to roll me out level and then just wait while he pulls up right into my guns and then I follow him up. Notice also that we're pretty much co-E. In the end, the whole point to the NRG fight is to bleed the other guy down and then convert your stored NRG into angles for the kill. If you can't bleed the guy down then it probably isn't going to work.
Last, I mentioned that this was a good example of NRG fighters versus an angles fighter but what really happened? I didn't fight an angles fight, I fought an NRG fight from beginning to end. Even though I was in what everyone would consider to be an angles fighter I didn't get slow and countered their NRG fight with some short extensions and isolation while keeping track of the second bandit and being aggressive in neutralizing one fighter (or letting him neutralize himself in the 109's case) so I could attack the other.