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
Red Sox 361 Indians 260 -7.7
-0.9
Blue Jays 271 Brewers 305 +0.9
-0.1
Tigers 310 Phillies 195 -0.4
+0.0
Pirates 247 Rays 191 -0.4
White Sox 200 Americans 164 +0.3
-0.2
Week of 4/17100.0*Chance in playoffs100.0*Average seed
Twins 232 Pirates 218 +0.4
+0.0
Indians 192 Nationals 281 Out
-1.1
Brewers 298 White Sox 277 +0.1
-0.1
Americans 217 Tigers 230 +0.1
+0.1
Rays 194 Red Sox 226 +0.0
Phillies 225 Blue Jays 294 +0.1
Week of 4/24100.0*Chance in playoffs100.0*Average seed
Indians 266 Twins 250 +0.5
Phillies 202 White Sox 258 +0.1
Brewers 257 Americans 351 -0.0
Games Above .500
Chance Will Make Playoffs