Maybe this is a little too abstract of a question? I'll post it anyway.
Are the 10 KOF games on the Neo Geo kind of randomly good and bad, or is there a pattern like the even titles seemingly being better than odd ones?
These kinds of coincidences were generated indirectly by the development method that of the SNK employed.
Unlike the competition, 'The King of Fighters' has always been a series where the plot was a relevant factor, so, if you really want to look for a narrative algorithm within this franchise, SNK has always generated its sagas thinking of them how of the trilogies: to which however the company always added an additional chapter, which was completely disconnected from the point of view of the plot (therefore 3 + 1).
Narratively the first chapter of a saga is basically the introduction, in the second the development takes place and in the third there is both the turning point and the conclusion: in the Orochi and in the Nest Saga the 'additional chapter' I mentioned before has been published as a gameplay perfecting, while in the Ash period the dream match episode has been a simply a 'accident' (the twelfth chapter), because they were basically planning 'KOF XIII', but they had spent all the money to create the new high definition graphics with their respective animations.
At this point only 'KOF' 94' remains uncovered by the count, but according to the developers the latter was only a test bed to test the interest of the public, in fact, if it did not sell enough the project would have been suppressed: just like it happened with the small saga of 'Fūun' ('Savage Reign' and 'Kizuna Encounter'), in this regard, have you ever noticed that officially it is only 'KOF' 95' to be considered the first chapter of the of Orochi saga? (Not to mention that the latter is a simple revisited 'KOF' 94' [as if to indicate a new start on the part of the company]).
In conclusion, the 'heavyweights' were released during the fourth release of a saga, which coincidentally were also of the even numbers, however, all of this it was a simple involuntary tradition, because this type of sequence has already been broken by the publication of 'KOF XIII', which despite being considered one of the best chapters is an odd number, moreover, even looking only the period of the NEOGEO, 'KOF '95' and 'KOF' 97' (odd numbers) have superior gameplay to the precursors 'KOF' 94' and 'KOF '96' (even numbers).