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Message: <blockquote data-quote="trptjoe" data-source="post: 3586983" data-attributes="member: 138432">Jeff Thomas, an occasional contributor to the 2016 thread, came up with a system for comparing Big Years. It isn't a percentage of possible species (which I'm sure Jeff could easily do, as he's kept track of all the ABA changes), but a formula for comparing birding years. Jeff calls it the X-factor. He gets full credit for this: X = C - MC is the number of Coded Birds (Codes 3, 4, 5 & 6).M is the number of missed Code 1 and Code 2 (regular) species.Jeff's sheets, even more comprehensive than mine, also keep track of X. I don't think he's up to speed yet this year, but he'll get there.If you look at my sheets you'll see some numbers in bold at the very bottom. That indicates that a birder "closed out" either the Code 1 and/or Code 2 species for the year. As we all know, Olaf and John had unprecedented success last year; they are also the only two birders to get all the Codes 1 & 2 in a single year.Their X-factor is easy to calculate: John is at 112 (109+3) and Olaf at 107 (105+2). The previous record was Sandy Komito in 1998, who had a 91. He had 96 coded birds and missed five regular birds. Laura Keene had a C of 92 (89+3) and missed two regular birds, for an X-factor of 90. As many of us have discussed, Laura's year was incredible from an historical standpoint. And Sandy's two years rank as #3 all-time (91 in 1998) and #5 all-time (82 in 1987). Christian nailed all but one regular bird, so his X-factor is 81 (C=82 - M=1).For the moment, I'm still counting the Condor as a 6; Jeff counts it as a 2, which is what the code was back in the day. Anyone can figure out the rest from my "By Code" sheet, but Neil Hayward had an 80 and John Vanderpoel a 79; there's a drop-off after that.Again, all credit goes to Jeff! (well, and the Big Year birders)Joe</blockquote>

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