I've got 7,945 Cubs cards from 40 different brands listed on a spreadsheet. A random number generator picked five cards, one each from the past several decades.
1950's / 1960's Topps 1958 #201 Jim Bolger This is not one of Topps' better looking cards. The bespectacled outfielder played in a career high 112 games in 1957 and was looking forward to an even better season in 1958. But his average dropped by 50 points and that led to a cut in playing time. After the season, the Cubs traded him to Cleveland.
1970's Kelloggs 1970 #40 Ernie Banks Here's another card from the Kelloggs set that shows a Cubs player in his home uniform while the Mets home is in the background. It was very unsettling for this Cubs fan to see when he was eight years old, and it still is now!
Mr. Cub was on his last legs (actually, it was his knees that were giving him problems) in 1970. He did hit his 500th career home run in May, but he played in only 72 games for the season and hit 12 home runs, both being the lowest since his rookie season.
1980's: Topps Traded 1986 #76 Jerry Mumphrey To get Mumphrey from the Astros in the winter of 1985, the Cubs swapped unproven youth (Billy Hatcher) for an aging veteran. He started 70 games for the '86 Cubs and pinch hit in another 41. He put up decent numbers, hitting .304.
1990's: Fleer 1997 #277 Tyler Houston 1997 would be Houston's first full season with the Cubs, having come over from the Braves in June, 1996. He shared the duties behind the plate with Scott Servais, playing in 72 games. He hit .260 with 2 homers and threw out 18% of those trying to steal. Nothing too earth-shattering there.
2000's: Allen & Ginter Relic 2006 #MP Mark Prior This is the first time the random number generator selected a relic card. By 2006, a Mark Prior relic wasn't worth too much. He had a dominating season in 2003, leading the Cubs to the brink of the pennant. But he was hurt for parts of the next three seasons and was never the same. 2006 was his last year in the majors, and he was really bad; 1-6 with a 7.21 ERA bad. He's been rehabbing and trying to come back ever since then. Most recently, he has hooked up with Orange County Flyers of the independent Golden Baseball League.