The game of chomp is an example of a game with very simple rules, but no known winning strategy in general. 


I copy the rules from [Ivars Peterson's page](https://web.archive.org/web/20110801000000*/http://www.maa.org/mathland/mathtrek_03_24_03.html):



> 
> Chomp starts with a rectangular array of counters arranged neatly in rows and columns. A move consists of selecting any counter, then removing that counter along with all the counters above and to the right of it. In effect, the player takes a rectangular or square "bite" out of the array—just as if the array were a rectangular, segmented chocolate bar. Two players take turns removing counters. The loser is the one forced to take the last "poisoned" counter in the lower left corner.
> 
> 
> 


A nice non-constructive argument shows that the first player has a winning strategy. The winning strategy can be made explicit in very specific cases. As far as I know, the more general setting for which the winning strategy is known is when we have 3 rows and any number of columns, see this [page](http://www.math.rutgers.edu/~zeilberg/mamarim/mamarimhtml/chomp.html).


My question is:



> 
> Are there any recent advances on chomp? 
> 
> 
> 



Winning strategy at chomp (a chocolate bar game)?
Here are two papers, from 2002 and 2007; not sure if they are new to you.


Jan Draisma and Sander van Rijnswou show in their paper,
"[How to chomp forests, and some other graphs](http://www.math.unibas.ch/%7Edraisma/recreational/graphchomp.pdf)" (2002),
that Chomp can be completely solved when the underlying graph $G$ is a forest.
From the Abstract:



> 
> Interesting consequences are: ﬁrst, that the starting
> player has a winning strategy for any non-empty tree; and second, that he has a
> winning strategy for the complete graph on $n$ vertices if and only if $n$ is not a
> multiple of 3.
> 
> 
> 


A second relatively recent paper is, "Scaling, Renormalization, and Universality in Combinatorial Games: The Geometry of Chomp," by Eric J. Friedman and Adam Scott Landsberg
([*Combinatorial Optimization and Applications*,
Lecture Notes in Computer Science, 2007, Volume 4616/2007, 200-207](https://doi.org/10.1007/978-3-540-73556-4_23)).
Their results resist succinct summary, but, for example,
they are able to compute "the expected number
of winning moves" under certain circumstances.


