How are these numbers calculated?

Big Games

How we did last week and who we should root for this week.   Explain

Week of 4/10100.0*Chance in playoffs100.0*Average seed
White Sox 200 Americans 164 -15.9
-1.9
Blue Jays 271 Brewers 305 +2.5
+0.1
Pirates 247 Rays 191 -1.0
-0.0
Red Sox 361 Indians 260 -0.4
+0.0
Tigers 310 Phillies 195 -0.4
+0.1
Nationals 169 Twins 250 -0.2
-0.0
Week of 4/17100.0*Chance in playoffs100.0*Average seed
Americans 217 Tigers 230 -0.5
-0.2
Brewers 298 White Sox 277 +0.2
-0.0
Rays 194 Red Sox 226 +0.1
Twins 232 Pirates 218 -0.1
-0.1
Phillies 225 Blue Jays 294 +0.1
Indians 192 Nationals 281 -0.0
Week of 4/24100.0*Chance in playoffs100.0*Average seed
Brewers 257 Americans 351 +1.5
Indians 266 Twins 250 -0.6
Phillies 202 White Sox 258 +0.1
Rays 179 Nationals 289 +0.0
Games Above .500
Chance Will Make Playoffs