Prompted by a discussion about the Mets potentially rehiring Bobby Valentine as their manager I decided to take a look back at baseball history to see if it could tell us anything about the merit (or lack thereof) of an organization rehiring a former manager.  Hat tip to fellow author Prismo whose comment spurred me to do the research.  To save some time I arbitrarily decided to make 1950 a cutoff date so the information below does not include any activity prior to that year.  So below are mostly facts with a few of my opinions thrown in here and there about the last 60 years of MLB manager rehires.  Let your taste decide.The Atlanta Braves rehired Bobby Cox. In his initial tenure of 1978-1981 the team went 266-232 .451, in his 2nd tenure of 1990-2010 the team went 1883-1386 .576.  In the first full year of his 2nd tenure the team went to the World Series but lost in 7 games.  Overall during his 2nd tenure the team finished in 1st place 14 times and including 2010 appeared in 15 post seasons, winning the World Series in 1995.  I think it's safe to describe his rehiring as an unqualified success.The Milwaukee Brewers rehired George Bamberger (the same guy I named when asked by fellow author Rusty a long time ago to name "the worst Mets manager").  In his initial tenure, 1978-1980, the team went 235-180 .566, but in the pre-wild card era failed to make the post season.  In each of the subsequent 2 seasons following his firing the team made the playoffs under 2 different managers, Buck Rodgers and Harvey Kuenn (when the team was known as "Harvey's Wallbangers"). Bamberger was rehired in 1985 and in his 2nd tenure the team went 142-171 .454.  The 1st Bamberger era resulted in a better won-loss record than the 2nd but neither featured a post season appearance.  For those who don't know Bamberger managed the Mets in 1982 and part of 1983 to an overall record of 81-127 .389.  Both years the team finished in last place in their division.The Pittsburgh Pirates rehired (and rehired, and rehired) Danny Murtaugh. In his initial tenure, 1958-1964, the team went 605-547, .525, making the post season once which produced the 1960 World Series championship.  In his 2nd tenure the team went 39-39 .500, in his 3rd! tenure, 1970-1971, the team went 186-138 .574, made the post season both years and won the World Series in 1971.  In Murtaugh's 4th!! and final tenure the team went 285-226 .558 from 1974-1976, losing the NLCS in each of the 1st 2 years.  The many Murtaugh rehirings produced positive results for the Pirates franchise overall.  Murtaugh passed away in December 1976 and for the sake of the fans of Pittsburgh I can only hope the organization is working closely with the Disney Corporation on reanimating Mr. Murtaugh.The San Francisco Giants rehired Bill Rigney. In his initial tenure, 1956-1960, the team went 332-342 .493.  Then in his 2nd tenure which came much later in 1976 the team went 74-88 .457.  The team had 2 winning seasons of the 6 total under Rigney but never appeared in the post season.The Yankees rehired Ralph Houk. In his initial tenure, 1961-1963, the team went 309-176 .529, winning the World Series in 1961 & 1962, then losing it in 1963.  In his 2nd tenure, 1966-1973, the team went 635-630 .502 but while having an overall winning record the team never reached the post season in Houk's 2nd go 'round.  The Yankees also rehired Billy Martin so many times in so many convoluted ways that I just really don't feel like doing the research necessary to determine exactly when he was or was not in charge.  What I can tell you for sure is that the team lost the 1976 World Series then won it in 1977 under Martin in what may safely be described as his initial tenure.  After that he shows up periodically between 1979-1988, his overall record as the Yankees manager is 556-385 .591, and the team never had a winning percentage lower than .536 with Martin at the helm.The Boston Red Sox rehired Pinky Higgins. In his initial tenure, 1955-1959,  the team went 360-329 .522, with 2 finishes of 3rd place in their division being the high water mark.  In his 2nd tenure, 1961-1962, the team went 200-227 .468, finishing 6th and 8th respectively.The Toronto Blue Jays rehired Cito Gaston. In his initial tenure, 1989-1997, the team went 683-636 .518, with 4 1st place finishes and back-to-back World Series titles in 1992-1993.  The team rehired Gaston in the middle of 2008 and he remained through the end of the 2010 regular season, compiling a record of 211-201 .512 but no post season appearances.The Baltimore Orioles rehired Earl Weaver. In his initial tenure, 1968-1982, the team went 1354-919 .596, with 6 1st place finishes, 3 AL Pennants and the 1970 World Series championship.  His 2nd tenure was 1985-1986 and the team went 126-141 .472 finishing in 4th and 7th place respectively.The Kansas City, later Oakland, Athletics rehired Alvin Dark. In his initial Kansas City tenure, 1966-1967, the team went 126-155 .448.  Then in Dark's 2nd go 'round in Oakland in 1974-1975 the team went 188-136 .580, winning the World Series in 1974 and losing the ALCS the following year.The then California Angels rehired Gene Mauch. In his initial tenure, 1982, the team went 93-69 .574 and lost the ALCS.  In his 2nd tenure 1985-1987, the team went 257-229 .529, making the post season in 1986 when they lost the ALCS.More than 1 organization did rehire a former manager for an interim stint of less that 1 full season but those were not considered relevant to the discussion and have not been included here.