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
Blue Jays 271 Brewers 305 -19.6
-1.6
White Sox 200 Americans 164 +2.7
+0.2
Pirates 247 Rays 191 -1.4
Tigers 310 Phillies 195 +0.5
+0.0
Nationals 169 Twins 250 -0.2
-0.0
Week of 4/17100.0*Chance in playoffs100.0*Average seed
Phillies 225 Blue Jays 294 +4.0
+1.1
Brewers 298 White Sox 277 -1.4
+0.1
Rays 194 Red Sox 226 +0.7
+0.1
Twins 232 Pirates 218 -0.4
-0.3
Americans 217 Tigers 230 +0.0
Indians 192 Nationals 281 -0.0
Week of 4/24100.0*Chance in playoffs100.0*Average seed
Blue Jays 251 Tigers 123 +51.5
+1.8
Indians 266 Twins 250 +14.8
+0.2
Brewers 257 Americans 351 +6.0
+0.2
Red Sox 236 Pirates 187 +4.0
+0.2
Rays 179 Nationals 289 -2.3
+0.1
Phillies 202 White Sox 258 +0.5
+0.1
Games Above .500
Chance Will Make Playoffs