How are these numbers calculated?

Big Games

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

If winner is:HomeDrawAway
Week of 9/20100.0*Chance in playoffs100.0*Average seed
Italy vs Namibia+18.5+2.1-18.6
+2.6-0.1-2.6
Italy vs Canada+18.5+2.1-18.6
+2.6-0.1-2.6
New Zealand vs South Africa+0.0-1.4+0.0
+0.0-0.2+0.0
Australia vs Fiji-0.0+0.1-0.0
Japan vs Russia+0.0-0.0-0.1
Ireland vs Scotland-0.0+0.1-0.0
Russia vs Samoa-0.0+0.1-0.0
France vs Argentina-0.0+0.1-0.0
England vs United States-0.0+0.1-0.0
Wales vs Georgia-0.0+0.1-0.0
England vs Tonga-0.0+0.1-0.0
Fiji vs Uruguay-0.0+0.1-0.0
If winner is:HomeDrawAway
Week of 9/28100.0*Chance in playoffs100.0*Average seed
South Africa vs Namibia+0.0-1.4+0.0
+0.0-0.2+0.0
New Zealand vs Canada+0.0-1.4+0.0
+0.0-0.2+0.0
Japan vs Ireland+0.0-0.0-0.1
Ireland vs Russia-0.0+0.1-0.0
Scotland vs Samoa-0.0+0.1-0.0
Georgia vs Fiji-0.0+0.1-0.0
Australia vs Wales-0.0+0.1-0.0
Georgia vs Uruguay-0.0+0.1-0.0
Argentina vs Tonga-0.0+0.1-0.0
France vs United States-0.0+0.1-0.0

What If

Chances based on how well the Italy finish out the regular season.   Explain

100100100100100100100100100100100100100100100100100100100100
If finish:Chance inChance will finish regular season at seed
TPW-OTLDplayoffs1234567891011121314151617181920Count
164-000In52351211,679,076,558
143-001In1444338000169,638,319
123-01097.1%210192220157230006,702,162,036
2-002100.01921272314510006,438,849
102-01179.7000212272811182000508,893,924
1-00385.20041529271013200109,203
82-02025.00000138121315141311620000010,053,033,834
1-01219.70002612101518171262000012,883,934
0-00413.60149413272414410684
61-0210.000002924332381000508,903,643
0-0130.400019253422710108,622
41-030Out000139151820181246,702,162,260
0-022Out0000151629281746,441,310
20-031Out0006264425169,628,417
00-040Out1931591,679,016,007
Total:40.0%4555555565555555555528,198,497,600
Points
Chance Will Make Playoffs