Interesting analysis. My own estimate, an educated guess, I would say that 998 names out of 1000 won't work. (998 / 1000). Looking at series, the letter (A) is RUX(A)DGJ. The A is the letter you're trying to (0,3,6,9) attach to a letter in EBEORIETE METHHPITI. Only the R works, A=R (9). So that says that a name can't have 2 A's to qualify as a (0,3,6,9,) match to the unknown 18. The same is true for D. UXA(D)GJM. D only equals M. Can't have DD, can't have AA. Those 2 alone might disqualify 15-20 percent of the names, I'm guessing. Look at the series WZC(FILORUXA)DGJ. FILORUXA matches to the unknown 18 with (IIIOR). So, there can be no more than 5 of any of those letters(FILORUXA) with two A's as an automatic disqualifier. That's one that's hard to pass because AILOR are commonly used. And then WZC(FILORUXADGJMPS)VYB matches the unknown 18 with IIIORMPB, so there can be no more than 8 of FILORUXADGJMPS, if I'm not mistaken. UXA(DGJMP)SVY. Matches the unknown 18 with MP, so no more than 2 of DGJMP. UXA(DGJMPS)VYB matches with MPB, no more than 3 of DGJMPS with 2 D's as automatic disqualifier. What I could do is put up all the important combinations that disqualify a name. For example these combinations disqualify a name, if I didn't err: AA DD DGJ DGM DGP GJM GJP JMP GGG JJJ MMM PPP DGJS DGMS DGPS JMPS DJMS DJPS JSJS PSPS SSSS TTTT TTTW TWTW WTWW (FILORUXA)---(Can't have six.) Well, that's sort of a rough draft and I may have made some mistakes, but it's difficult to squeeze a name through there. The coincidence here, as I see it, is that it's difficult to get an 18 letter name thru this unknown 18 (0,3,6,9,) Caesar shift, but yet, by chance, another serial murderer that used letter-writing with talk of bombs, gets thru-his name gets thru the difficult 0,3,6,9 Caesar maze. To me, that's a striking coincidence.