Question: Near what river was German and Canadian professional poker player born?

Context paragraphs:
Andy Frankenberger: Andy Frankenberger is a professional poker player and former equity derivatives trader from New York City.  In his first year as a professional poker player, Frankenberger was named World Poker Tour (WPT) Season IX Player of the Year.  Card Player Magazine described this as one of poker's best rookie years in a September 2011 cover story.  Frankenberger followed this up by winning back to back bracelets at the World Series of Poker in 2011 and 2012.  He has been prominently featured in financial media including The Wall Street Journal, Fox Business Network, and Bloomberg Television.

Viacheslav Zhukov: Viacheslav Zhukov (c. 1989) is a Russian professional poker player who has won two World Series of Poker bracelets. Prior to becoming a professional poker player, Zhukov was a geologist in Russia.  he has career earnings of $940,000, $838,000 of which was earned at the World Series of Poker.

Dag Palovic: Dag Palovič (* 4 January 1975, Bratislava) is a Slovak professional poker player, businessman and a former TV host.  Since 1 January 2011, he is a member of PokerStars Team Pro, first and as of October 2011 only sponsored poker player from Slovakia.  He is best known for making two European Poker Tour (EPT) final tables as well as being the only player from Slovakia who has cashed in the World Series of Poker (WSOP) Main Event, finishing 120th in 2009 and 37th in 2010.  As of March 2013, he is second leading Slovak all time money list with career earnings of $909,405 and is also an author of first Slovak poker book on poker titled "Ako sa stať poker pro" (How to become a poker pro), co-authored by 1983 World Series Of Poker champion Tom McEvoy.  From 2000 until 2004 he was CEO and Chairman Of The Board of Directors of "ad pepper media Slovakia, a.s.", the daughter company of one of the world´s leading e-Adverising german-dutch agency "ad pepper media International N.V." for Slovak and Czech Republic.

Schaffhausen: Schaffhausen (] ; Alemannic German: "Schafuuse" ; French: "Schaffhouse" ; Italian: "Sciaffusa" ; Romansh: "Schaffusa" ; English: Shaffhouse ) is a town with historic roots, a municipality in northern Switzerland, and the capital of the canton of the same name; it has an estimated population of 36,000 as of December 2016 .  It is located right next to the shore of the High Rhine; it is one of four Swiss towns – besides Neuhausen a. Rhf. , the historic Neunkirch and Stein a. Rh.  – that is located on the northern side of the Rhine.

Howard Lederer: Howard Henry Lederer (born October 30, 1963) is an American professional poker player.  He has won two World Series of Poker bracelets and holds two World Poker Tour titles.  Lederer has also contributed to several books on poker strategy and has provided commentary for poker programming.  He is known by poker fans and players as "The Professor" and is the older brother of professional poker player Annie Duke.

Gavin Smith (poker player): Gavin Smith (born September 4, 1968 in Guelph, Ontario) is a Canadian professional poker player who won the World Poker Tour's Season IV Mirage Poker Showdown Championship event and the WPT Season IV Player of the Year award in 2005, then at the 2010 World Series of Poker he won the $2,500 Mixed Hold'em event along with his first bracelet.

Billy Baxter (poker player): William E. Baxter, Jr. (born 1940) is an American professional poker player and sports bettor.  He has won numerous tournament titles in his career as a professional poker player, including seven World Series of Poker bracelets.

Tommy Angelo (poker player): Tommy Angelo (born August 25, 1958) is an Oakland, California professional poker player, writer, and coach.  Angelo was a career musician in the 1980's, performing rock and country on drums and piano.  In 1990, he became a full-time professional poker player.  Since then has since written 100 magazine articles, written and produced 18 poker training videos, and written and published three books on poker.

Daniel Negreanu: Daniel Negreanu ( ; born July 26, 1974) is a Canadian professional poker player who has won six World Series of Poker (WSOP) bracelets and two World Poker Tour (WPT) championship titles.  The independent poker ranking service Global Poker Index (GPI) recognised Negreanu as the best poker player of the decade in 2014.

Greg Mueller: Greg Mueller (born 2 June 1971) is a German and Canadian professional poker player and former professional ice hockey defenceman.  Mueller was born in Schaffhausen, Switzerland.

Supporting paragraphs: Greg Mueller Schaffhausen
Answer: Rhine