Many players were a threat to Evert on clay by that period. Jaeger beat her back to back times on clay, including troucing her badly in the FO semis. Maleeva crushed her in the Rome final, and nearly beat her a number of other times. The clay court great Zina Garrison beat her in straight sets to win a tier 1 title. Meanwhile in the 70s high quality clay courters like Goolagong and Nancy Richey couldnt beat her once for 6 years. Yes she had developed a stronger physical game by the mid 80s, but she was nowhere near as consistent, patient, or deadly focused as she used to be, something she admited herself, and which is most paramount on clay.
Fine though, you believe 82-86 and especialy 84-86 was Chris's apex on clay. If we take that as being true she took a straight sets loss in a tournament final on clay to a 16 year old/0 titles/1 time past the round of 16 of a slam Graf, I guess that already answers the thread question, atleast as far as Graf is concerned. Not to mention if Martina was able to crush Evert at her career clay best (according to you) by scores like 6-3, 6-1 and 6-2, 6-0 on clay, then how she would fare vs much superior clay courters than Martina such as Graf, Seles, and possibly Henin in their primes is already self explanatory.
Jaeger and Maleeva are examples of the improved slow court games of the next generation, using many of the same tools, strokes and tactics that Evert had first employed. Her problem wasn't clay or early errors or more impatience or poorer performance per se. It was pschological ( in her head) and tactical, trying to find ways to crack the safe she had built. They built their games on not making errors and that two hander. Goolagong, and Richey and King and Wade and court, and Casals, and Durr, did not. Rallies lasted longer and more was expected of her point after point than before. She had to learn to break up other's rhythm, a skill she did not need in the 70's when no one had any!
You keep pointing to a score or a result to disprove a generalization. I can find those scores to, for any player. This is why I so hate these 'peak' year discussions. Tennis don't work like that. Bad matches can crop up in anyone's career, even their peak. Correspondingly great play can sparkle well before or after. By '86 she had definitely begun to have intermittant lapses in concentration that affected her clay game
first , then hard, and her grass game last. And Graf began to realize her incredible potential long before it was habitual. It explains why Martina can take a set in '75 from Evert and loose most of them badly on the same surface before or after until the mid eighties. It explains why the same 16 year old who Evert routed in straight sets, she lost to in straight sets
about a month later. neither player changed that much between the Lipton and Hilton Head. It explains why the same woman who played so lousy in the first set of the RG final 2 -6, can end up playing her most exquisite clay tennis the next two.6-3, 6-3. Hell, she continued to produce some fantastic clay tennis through '88 where it all came together, the old and new EVert. But never enough to win a two week event, and rarely enough to win a one week event.
Nadalagassi, you do not realize what Evert's real genius was. It wasn't her patience, her 'mental toughness, her perfect groundstrokes, etc. It was problem-solving. Time after time from the juniors unitl retirement, Evert faced stronger, faster , more agressive or and later even steadier threats who could take her down once or twice pretty badly. But given time, she would find keys to unlock the mystery, and practice the skills needed to execute. The clay gave her more time to do the above, and more balls to practice perfecting the patterns. I don't see how anyone dare right her off vs Seles or Graf when I think she was already trying keys in their locks in '88, '89.
For the record, I am very iffy about who comes out on top between Graf and Evert in a series. If its best of three Graf wins without a doublt. , If its best of 5 or 10 I give the edge to Chris.