▁through ▁th ir teenth ▁ed itions , ▁assuming ▁editor ship ▁starting ▁with ▁M CO - 8 ▁in ▁ 1 9 5 2 . ▁K orn ▁was ▁assist ed ▁on ▁certain ▁ed itions ▁by ▁Jack ▁Collins , ▁Larry ▁Evans , ▁and ▁Nick ▁de ▁F irm ian ; ▁Evans ▁and ▁de ▁F irm ian ▁have ▁held ▁the ▁U . S . ▁Championship . ▁ ▁The ▁first ▁twelve ▁ed itions ▁used ▁descript ive ▁notation ▁to ▁record ▁the ▁moves , ▁and ▁only ▁with ▁M CO - 1 3 ▁in ▁ 1 9 9 0 ▁did ▁the ▁series ▁begin ▁to ▁use ▁the ▁now - standard ▁algebraic ▁notation . ▁The ▁most ▁recent ▁edition , ▁M CO - 1 5 ▁in ▁ 2 0 0 8 , ▁was ▁written ▁and ▁edited ▁by ▁de ▁F irm ian . ▁ ▁Since ▁ 1 9 8 0 , ▁there ▁have ▁been ▁other ▁one - volume ▁opening ▁en cyc loped ias ▁to ▁rival ▁M CO : ▁B ats ford ▁Ch ess ▁Open ings ▁( B CO ) ▁in ▁ 1 9 8 2 ▁and ▁ 1 9 8 9 , ▁N unn ' s ▁Ch ess ▁Open ings ▁( N CO ) ▁in ▁ 1 9 9 9 , ▁and ▁Paul ▁van ▁der ▁Ster ren ' s ▁Fund amental ▁Ch ess ▁Open ings ▁in ▁ 2 0 0 9 . ▁John ▁Watson ▁wrote ▁that ▁M CO - 1 3 ▁" re ally ▁isn ' t ▁up ▁to ▁modern ▁expect ations ", ▁but ▁called ▁M CO - 1 4 ▁" a ▁vast ▁improvement ▁over ▁its