I would argue that with just 2 more points, she would have won the 1988 Australian Open. Graf was losing her brains & was all kinds-of bent out of shape by that stage in the match... the young Chrissie would never have let her get off the hook by making those errors she produced after pulling ahead 6-5. The grim reaper evert would have slammed the door shut with a steel-trap bang. but there's your age issue, nevertheless.
I don't agree there at all. As well as Chris was playing, there was no way she was going to beat Graf that day. As was evident for the first set and a half, Graf clearly had the upper hand in that match. Even if Chris managed to get to a 3rd set by taking the 2nd set TB, Graf would have triumphed anyway. Not sure if it was age that sealed the deal. At that stage in their rivalry, Graf was the better player. It would have had to be the worst mental breakdown of Graf's career for Chris to come back and win.
You also mentioned in some post that Ms. Evert at some point during her career "allowed" some rivals, i.e., Navratilova, Austin, and Graf to beat her. Apologies if I am not quite getting the wording right. I also disagree with that sentiment. Especially with Austin and Graf.
First Graf: their rivalry was 8-6 in favor of Steffi. And it was pretty straightforward, Chris wins the first 6 all in straight sets, Steffi wins the next 8, 7 of which were straight sets. The 1986 FCC final was the obvious turning point. I do think age, nerves, and the improvement from Graf contributed to pushing Steffi over the psychological barrier of beating Chris. It's too bad they didn't play again in 1986, because I think Chris would have won had they met in the 86 French semis, or on grass. Once 1987 started, when Chris was coming back after a layoff, she didn't have the physical ability to beat Graf, and that was required from Chris at the time. Plus Steffi was at such a high level physically and mentally from 1987 until Chris retired that it wasn't so much Chris 'allowing' Graf to win, but Steffi not allowing Chris to even have a sniff at a chance at a win. I thought Chris pushing Steffi in the 1989 VS of Florida was Chris' last stand, perhaps of her career (save the 1989 whalloping of Seles at the Open). Chris was also a realist too. Her divorce from Lloyd, knee problems, and age contributed to her drop to #3 (and heavens! a temporary drop behind Hana in early 1987!). She may not have liked that but she accepted it. She remained in contention at the majors, especially in 1988 where she had the 2nd best record for the year. But Graf was clearly the better player, and I believe Chris realized it, even though she still put up a fight. I don't think it was the same dimension as her rivalry with Martina. The Steffi-Chris rivalry wasn't really on equal footing post 1986.
Now as for the much maligned Austin, I admit I never got why Chris had some mental block against Tracy. But I also think much has been overplayed and overdone about the 3 beatings Tracy inflicted on Chris in Jan 1980 - 3 straight set shellackings in 2 tournaments in a 10 day period. Those matches were indoors - Tracy's best surface and Chris' worst, and at a time when Chris was coming off the most vigorous playing schedule of her career. Not to mention her marriage and the burnout that occurred very shortly thereafter. Quite frankly, I don't think Chris really cared that much at the time, and Tracy happened to be the one to inflict the damage. You can't discount those wins because they happened. Still you eliminate those and Chris has an 8-6 edge. And as I have maintained, Chris was
the better player, no question. She got knocked off by Tracy on occasion, because Austin was a very good player. But when Chris set her mind to beating Tracy, she did. (And needing to get a little dig into Tracy, it would have been nice my dear if you had played some more clay events which Chris entered, i.e., the FCC post 1980, Amelia Island, or that tournament in Paris known as the French Open!)
It is conceivable Evert did cede much to Navratilova, but kind of like with Graf, she may have had no choice. For a time Navratilova was too strong physically and then mentally for Chris. I mean 12 matches in 1983-1984, and Chris wins two measly 6-4 sets!? Those 2 years may have been the only period, IMHO, of Evert's career where she mentally conceded the match to her opponent before it started, and was merely playing for a good showing. But proving the champion she was, Evert got up off the floor and made her way back, starting with the 1985 VS Florida final, where she played perfect tennis to stun Martina in straight sets.