Question: Was Summit or Crosstrack created in the 20th century, involve strategy, and was created by Milton Bradley?

full_context: Document 1: Hex (board game): Hex is a strategy board game for two players played on a hexagonal grid, theoretically of any size and several possible shapes, but traditionally as an 11×11 rhombus. Players alternate placing markers or stones (Go stones make ideal playing pieces) on unoccupied spaces in an attempt to link their opposite sides of the board in an unbroken chain. One player must win; there are no draws. The game has deep strategy, sharp tactics and a profound mathematical underpinning related to the Brouwer fixed-point theorem. It was invented in the 1940s independently by two mathematicians, Piet Hein and John Nash. The game was first marketed as a board game in Denmark under the name Con-tac-tix, and Parker Brothers marketed a version of it in 1952 called Hex; they are no longer in production. Hex can also be played with paper and pencil on hexagonally ruled graph paper.
Document 2: Summit (game): Summit is a Cold War board wargame introduced in 1961 by Milton Bradley as "The Top Level Game of Global Strategy", with an updated release in 1971. Each player chooses one of the major powers from the 1950s/1960s era and controlled their economic and military buildup during each turn, much like Risk.
Document 3: Summit (meeting): A summit meeting (or just summit) is a meeting of heads of state or government, usually with considerable media exposure, tight security, and a prearranged agenda. Notable summit meetings include those of Franklin D. Roosevelt, Winston Churchill, and Joseph Stalin during World War II. However, the term summit was not commonly used for such meetings until the Geneva Summit (1955). During the Cold War, when American presidents joined with Soviet or Chinese counterparts for one-on-one meetings, the media labelled the event as a "summit". The post–Cold War era has produced an increase in the number of "summit" events. Nowadays, international summits are the most common expression for global governance.
Document 4: Sigma I-66 war game: The Sigma I-66 war game was one of a series of classified high level war games played in The Pentagon during the 1960s to strategize the conduct of the burgeoning Vietnam War. These simulations were designed to replicate then-current conditions in Indochina, with an aim toward predicting future foreign affairs events. They were staffed with high-ranking officials standing in to represent both domestic and foreign characters; stand-ins were chosen for their expertise concerning those they were called upon to represent. The games were supervised by a Control appointed to oversee both sides. The opposing Blue and Red Teams customary in war games were designated the friendly and enemy forces as was usual; however, several smaller teams were sometimes subsumed under Red and Blue Teams. Over the course of the games, the Red Team at times contained the Yellow Team for the Peoples Republic of China, the Brown Team for the Democratic Republic of Vietnam, the Black Team for the Viet Cong, and Green for the USSR.
Document 5: Abstract strategy game: An abstract strategy game is a strategy game that does not rely on a "theme". Traditional abstract strategy games will conform to the strictest definition of: a gameboard, card, or tile game in which there is no hidden information, no non-deterministic elements (such as shuffled cards or dice rolls), and (usually) two players or teams taking a finite number of alternating turns.
Document 6: Shannon switching game: The Shannon switching game is an abstract strategy game for two players, invented by American mathematician and electrical engineer Claude Shannon, the "father of information theory" some time before 1951. Two players take turns coloring the edges of an arbitrary graph. One player has the goal of connecting two distinguished vertices by a path of edges of their color. The other player aims to prevent this by using their color instead (or, equivalently, by erasing edges). The game is commonly played on a rectangular grid; this special case of the game was independently invented by American mathematician David Gale in the late 1950s and is known as Gale or Bridg-It.
Document 7: Sigma war games: The Sigma war games were a series of classified high level war games played in the Pentagon during the 1960s to strategize the conduct of the burgeoning Vietnam War. The games were designed to replicate then-current conditions in Indochina, with an aim toward predicting future events in the region. They were staffed with high-ranking officials standing in to represent both domestic and foreign characters; stand-ins were chosen for their expertise concerning those they were called upon to represent. The games were supervised by a Control appointed to oversee both sides. The opposing Blue and Red Teams customary in war games were designated the friendly and enemy forces as was usual; however, several smaller teams were sometimes subsumed under Red and Blue Teams. Over the course of the games, the Red Team at times contained the Yellow Team for the People's Republic of China, the Brown Team for the Democratic Republic of Vietnam, the Black Team for the Viet Cong, and Green for the USSR.
Document 8: Connection game: A connection game is a type of abstract strategy game in which players attempt to complete a specific type of connection with their pieces. This could involve forming a path between two or more goals, completing a closed loop, or connecting all of one's pieces so they are adjacent to each other. Connection games typically have simple rules, but complex strategies. They have minimal components and may be played as board games, computer games, or even paper and pencil games.
Document 9: Sigma I-67 and II-67 war games: The Sigma I-67 and II-67 War Games were two of a series of classified high level war games played in the Pentagon during the 1960s to strategize the conduct of the burgeoning Vietnam War. The games were designed to replicate then-current conditions in Indochina, with an aim toward predicting future foreign affairs events. They were staffed with high-ranking officials standing in to represent both domestic and foreign characters; stand-ins were chosen for their expertise concerning those they were called upon to represent. The games were supervised by a Control appointed to oversee both sides. The opposing Blue and Red Teams customary in war games were designated the friendly and enemy forces as was usual; however, several smaller teams were sometimes subsumed under Red and Blue Teams. Over the course of the games, the Red Team at times contained the Yellow Team for the Peoples Republic of China, the Brown Team for the Democratic Republic of Vietnam, the Black Team for the Viet Cong, and Green for the USSR.
Document 10: Axis &amp; Allies: Axis & Allies is a series of World War II strategy board games. Originally designed by Larry Harris and published by Nova Game Designs in 1981, the game was republished by the Milton Bradley Company in 1984 as part of the "Gamemaster Series" of board games. This edition has been retroactively named Axis & Allies: Classic to differentiate it from later revisions. In 1996, "Axis & Allies: Classic" was inducted into the Academy of Adventure Gaming Arts & Design "Adventure Gaming Hall of Fame". "Games" magazine also has inducted "Axis & Allies" into their buyers' guide Hall of Fame, an honor the magazine extends to "games that have met or exceeded the highest standards of quality and play value and have been continuously in production for at least 10 years; i.e., classics."
Document 11: Twilight Struggle: Twilight Struggle: The Cold War, 1945–1989 is a card-driven strategy game for two players, with its theme taken from the Cold War. One player plays the United States (US), and the other plays the Soviet Union (USSR). The game takes its title from John F. Kennedy's inaugural address:
Document 12: Quoridor: Quoridor is a 2- or 4-player abstract strategy game designed by Mirko Marchesi and published by Gigamic Games. Quoridor received the Mensa Mind Game award in 1997 and the Game Of The Year in the USA, France, Canada and Belgium.
Document 13: Crosstrack: Crosstrack, the "unique track switching game", is an abstract strategy game created by Shoptaugh Games in 1994. Players place special track pieces onto an irregular octagon board, winning by being the first to create an unbroken path between two opposite sides.
Document 14: Crossings (game): Crossings is a two-player abstract strategy board game invented by Robert Abbott. The rules were published in Sid Sackson's "A Gamut of Games". Crossings was the precursor to Epaminondas, which uses a larger board and expanded rules.
Document 15: Diplomacy (game): Diplomacy is a strategic board game created by Allan B. Calhamer in 1954 and released commercially in 1959. Its main distinctions from most board wargames are its negotiation phases (players spend much of their time forming and betraying alliances with other players and forming beneficial strategies) and the absence of dice and other game elements that produce random effects. Set in Europe before the beginning of World War I, "Diplomacy" is played by two to seven players, each controlling the armed forces of a major European power (or, with fewer players, multiple powers). Each player aims to move his or her few starting units and defeat those of others to win possession of a majority of strategic cities and provinces marked as "supply centers" on the map; these supply centers allow players who control them to produce more units.
ground_truth: Summit