{ "id": "0710.3632", "version": "v3", "published": "2007-10-19T05:35:06.000Z", "updated": "2009-06-02T10:19:35.000Z", "title": "2-pile Nim with a Restricted Number of Move-size Imitations", "authors": [ "Urban Larsson" ], "comment": "18 pages, with an appendix by Peter Hegarty", "categories": [ "math.CO" ], "abstract": "We study a variation of the combinatorial game of 2-pile Nim. Move as in 2-pile Nim but with the following constraint: Suppose the previous player has just removed say $x>0$ tokens from the shorter pile (either pile in case they have the same height). If the next player now removes $x$ tokens from the larger pile, then he imitates his opponent. For a predetermined natural number $p$, by the rules of the game, neither player is allowed to imitate his opponent on more than $p-1$ consecutive moves. We prove that the strategy of this game resembles closely that of a variant of Wythoff Nim--a variant with a blocking manoeuvre on $p-1$ diagonal positions. In fact, we show a slightly more general result in which we have relaxed the notion of what an imitation is.", "revisions": [ { "version": "v3", "updated": "2009-06-02T10:19:35.000Z" } ], "analyses": { "subjects": [ "91A46" ], "keywords": [ "restricted number", "move-size imitations", "wythoff nim-a variant", "predetermined natural number", "combinatorial game" ], "note": { "typesetting": "TeX", "pages": 18, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2007arXiv0710.3632L" } } }