What a Difference Two Games Make!

B10 vs SEC schedules 2020

24 September 2020

The 2020 college football season is a mess, but the Big Ten's decision to play an 8-conference-game-only schedule actually gives us an opportunity to measure some of the effects of schedule topology on ratings that depend upon the connectivity of the games graph. That the SEC and now Big 10 are playing only conference schedules the D1 field as a whole is not connected.

Both leagues have two 7-team divisions so the schedules are asymmetric.

Schedules

B10

INMDMIMSOSPSRUILIAMNNENWPUWI
IN1111110000011
MD1111110010100
MI1111110010001
MS1111110100100
OS1111111001000
PS1111110101000
RU1111111000010
IL0000101111111
IA0001010111111
MN0110000111111
NE0000110111111
NW0101000111111
PU1000001111111
WI1010000111111

SEC

UFUGUKUMSCUTVUUAARAULSOMMSAM
UF1111110101101
UG1111111110010
UK1111111010110
UM1111111101010
SC1111110011101
UT1111111110001
VU1111110001111
UA0111010111111
AR1101010111111
AU0110110111111
LS1001101111111
OM1010101111111
MS0111001111111
AM1000111111111

The SEC's two extra games make its schedule more tightly connected than the Big Ten's.

Number of Common Opponents

B10

INMDMIMSOSPSRUILIAMNNENWPUWI
IN5655564444422
MD5665554424244
MI6655554424442
MS5655654244244
OS5555662442444
PS5556654242444
RU6555652444424
IL4444242556565
IA4442424556655
MN4224444555656
NE4444224665555
NW4242444566555
PU2444442655556
WI2424444556556

SEC

UFUGUKUMSCUTVUUAARAULSOMMSAM
UF6678788686686
UG6886866668868
UK6877776868668
UM7876776686868
SC8676788866686
UT7877766668886
VU8677868886666
UA8666868886686
AR6686868877677
AU8668668876777
LS6886686676878
OM6868686667878
MS8666886877776
AM6888666677886

Number of Paths 3 Edges Long

Diag[3]Team_16_17_18_19_20_21_22_23_24_25_26_27_28_29_40_41_42_43_44_45_46_47_48_49_50_51_52_53
36_16Indiana364340434343403130313030363600000000000000
36_17Maryland433640404343433031363036303100000000000000
36_18Michigan404036434343433030363031313600000000000000
36_19Michigan State434043364340433036313136303000000000000000
36_20Ohio State434343433640403631303630313000000000000000
36_21Penn State434343404036433136303631303000000000000000
36_22Rutgers404343434043363630303130363100000000000000
36_23Illinois313030303631363643434043404300000000000000
36_24Iowa303130363136304336434040434300000000000000
36_25Minnesota313636313030304343364340434000000000000000
36_26Nebraska303030313636314040433643434300000000000000
36_27Northwestern303631363031304340404336434300000000000000
36_28Purdue363031303130364043434343364000000000000000
36_29Wisconsin363136303030314343404343403600000000000000
66_40Florida000000000000006676767370737066726775746775
66_41Georgia000000000000007666707076707676747466667466
66_42Kentucky000000000000007670667373737374687467727467
66_43Missouri000000000000007370736676737374746872677467
66_44South Carolina000000000000007076737666737066677274756775
66_45Tennessee000000000000007370737373667674747467676872
66_46Vanderbilt000000000000007076737370766666676775757274
66_47Alabama000000000000006676747466746666707076767076
66_48Arkansas000000000000007274687467746770667373767373
66_49Auburn000000000000006774746872746770736676737373
66_50LSU000000000000007566677274677576737666707370
66_51Mississippi000000000000007466726775677576767370667370
66_52Mississippi State000000000000006774747467687270737373736676
66_53Texas A&M000000000000007566676775727476737370707666

Number of Paths 4 Edges Long

Diag[4]Team_16_17_18_19_20_21_22_23_24_25_26_27_28_29_40_41_42_43_44_45_46_47_48_49_50_51_52_53
324_16Indiana32430631530530630531527628027628028026426400000000000000
324_17Maryland30632431531530530630528027626428026428027600000000000000
324_18Michigan31531532430630530530628028026428027627626400000000000000
324_19Michigan State30531530632430631530528026427627626428028000000000000000
324_20Ohio State30630530530632431531526427628026428027628000000000000000
324_21Penn State30530630531531532430627626428026427628028000000000000000
324_22Rutgers31530530630531530632426428028027628026427600000000000000
324_23Illinois27628028028026427626432430630531530531530600000000000000
324_24Iowa28027628026427626428030632430631531530530500000000000000
324_25Minnesota27626426427628028028030530632430531530631500000000000000
324_26Nebraska28028028027626426427631531530532430630630500000000000000
324_27Northwestern28026427626428027628030531531530632430530600000000000000
324_28Purdue26428027628027628026431530530630630532431500000000000000
324_29Wisconsin26427626428028028027630630531530530631532400000000000000
734_40Florida00000000000000734700702711725711725728712724700704724700
736_41Georgia00000000000000700736724724700724700696704704728728704728
732_42Kentucky00000000000000702724732714711714711704720704724712704724
732_43Missouri00000000000000711724714732702714711704704720712724704724
734_44South Carolina00000000000000725700711702734711725728724712704700724700
732_45Tennessee00000000000000711724714714711732702704704704724724720712
734_46Vanderbilt00000000000000725700711711725702734728724724700700712704
736_47Alabama00000000000000728696704704728704728736724724700700724700
732_48Arkansas00000000000000712704720704724704724724732714711702714711
732_49Auburn00000000000000724704704720712704724724714732702711714711
734_50LSU00000000000000700728724712704724700700711702734725711725
734_51Mississippi00000000000000704728712724700724700700702711725734711725
732_52Mississippi State00000000000000724704704704724720712724714714711711732702
734_53Texas A&M00000000000000700728724724700712704700711711725725702734

Number of Paths 5 Edges Long

Diag[5]Team_16_17_18_19_20_21_22_23_24_25_26_27_28_29_40_41_42_43_44_45_46_47_48_49_50_51_52_53
2380_16Indiana2380242624012431242624312401226522502265225122512295229500000000000000
2380_17Maryland2426238024012401243124262431225022652295225122952251226500000000000000
2380_18Michigan2401240123802426243124312426225122512295225022652265229500000000000000
2380_19Michigan State2431240124262380242624012431225122952265226522952250225100000000000000
2380_20Ohio State2426243124312426238024012401229522652250229522512265225100000000000000
2380_21Penn State2431242624312401240123802426226522952251229522652251225000000000000000
2380_22Rutgers2401243124262431240124262380229522512251226522502295226500000000000000
2380_23Illinois2265225022512251229522652295238024262431240124312401242600000000000000
2380_24Iowa2250226522512295226522952251242623802426240124012431243100000000000000
2380_25Minnesota2265229522952265225022512251243124262380243124012426240100000000000000
2380_26Nebraska2251225122502265229522952265240124012431238024262426243100000000000000
2380_27Northwestern2251229522652295225122652250243124012401242623802431242600000000000000
2380_28Purdue2295225122652250226522512295240124312426242624312380240100000000000000
2380_29Wisconsin2295226522952251225122502265242624312401243124262401238000000000000000
7090_40Florida0000000000000070907196718671617111716171117088713671067187717471067187
7080_41Georgia0000000000000071967080711671167196711671967204717271727088708871727088
7100_42Kentucky0000000000000071867116710071467161714671617172712671697106713671697106
7100_43Missouri0000000000000071617116714671007186714671617172716971267136710671697106
7090_44South Carolina0000000000000071117196716171867090716171117088710671367174718771067187
7100_45Tennessee0000000000000071617116714671467161710071867172716971697106710671267136
7090_46Vanderbilt0000000000000071117196716171617111718670907088710671067187718771367174
7080_47Alabama0000000000000070887204717271727088717270887080711671167196719671167196
7100_48Arkansas0000000000000071367172712671697106716971067116710071467161718671467161
7100_49Auburn0000000000000071067172716971267136716971067116714671007186716171467161
7090_50LSU0000000000000071877088710671367174710671877196716171867090711171617111
7090_51Mississippi0000000000000071747088713671067187710671877196718671617111709071617111
7100_52Mississippi State0000000000000071067172716971697106712671367116714671467161716171007186
7090_53Texas A&M0000000000000071877088710671067187713671747196716171617111711171867090
The remainder of the D1 field is connected by paths no more than 5 edges long. By this time there are more than three times the number of connections between pairs of SEC teams than between pairs of Big Ten teams – an average of 7146.7 to 2337.5.

Another difference is evident when we compare the size and number of scheduled round-robins. There are 29 subsets of SEC teams where each member plays all of the others, with orders 4, 5, 6 and 7. All of the 14 interdivisional round robins in the Big Ten schedule are order 3.

#Teams
7{ Illinois; Iowa; Minnesota; Nebraska; Northwestern; Purdue; Wisconsin }
7{ Indiana; Maryland; Michigan; Michigan State; Ohio State; Penn State; Rutgers }
3{ Penn State; Iowa; Nebraska }
3{ Indiana; Purdue; Wisconsin }
3{ Ohio State; Rutgers; Illinois }
3{ Michigan State; Penn State; Iowa }
3{ Indiana; Michigan; Wisconsin }
3{ Indiana; Rutgers; Purdue }
3{ Michigan State; Iowa; Northwestern }
3{ Rutgers; Illinois; Purdue }
3{ Ohio State; Illinois; Nebraska }
3{ Ohio State; Penn State; Nebraska }
3{ Maryland; Minnesota; Northwestern }
3{ Maryland; Michigan State; Northwestern }
3{ Michigan; Minnesota; Wisconsin }
3{ Maryland; Michigan; Minnesota }
#Teams
7{ Florida; Georgia; Kentucky; Missouri; South Carolina; Tennessee; Vanderbilt }
7{ Alabama; Arkansas; Auburn; LSU; Mississippi; Mississippi State; Texas A&M }
6{ Florida; South Carolina; Vanderbilt; LSU; Mississippi; Texas A&M }
5{ South Carolina; Auburn; LSU; Mississippi; Texas A&M }
5{ Georgia; Kentucky; Missouri; Vanderbilt; Mississippi State }
5{ Florida; Missouri; South Carolina; Vanderbilt; LSU }
5{ Tennessee; Alabama; Arkansas; Auburn; Texas A&M }
5{ Florida; South Carolina; Tennessee; Vanderbilt; Texas A&M }
5{ Georgia; Kentucky; Missouri; Alabama; Mississippi State }
5{ Georgia; Kentucky; Missouri; Tennessee; Alabama }
5{ Florida; Arkansas; LSU; Mississippi; Texas A&M }
5{ Florida; Kentucky; South Carolina; Vanderbilt; Mississippi }
5{ Vanderbilt; LSU; Mississippi; Mississippi State; Texas A&M }
5{ Missouri; Alabama; Arkansas; LSU; Mississippi State }
5{ Kentucky; Alabama; Auburn; Mississippi; Mississippi State }
5{ Georgia; Kentucky; Alabama; Auburn; Mississippi State }
5{ Georgia; Kentucky; Tennessee; Alabama; Auburn }
5{ Georgia; Kentucky; South Carolina; Tennessee; Auburn }
5{ Georgia; Alabama; Arkansas; Auburn; Mississippi State }
5{ Georgia; Tennessee; Alabama; Arkansas; Auburn }
5{ Georgia; Missouri; Alabama; Arkansas; Mississippi State }
5{ Georgia; Missouri; Tennessee; Alabama; Arkansas }
5{ Florida; Georgia; Missouri; Tennessee; Arkansas }
4{ Florida; Tennessee; Arkansas; Texas A&M }
4{ Florida; Missouri; Arkansas; LSU }
4{ Kentucky; Vanderbilt; Mississippi; Mississippi State }
4{ South Carolina; Tennessee; Auburn; Texas A&M }
4{ Missouri; Vanderbilt; LSU; Mississippi State }
4{ Kentucky; South Carolina; Auburn; Mississippi }

It will be interesting to see how rating systems treat these two disconnected islands in D1. After the (ir)regular season I'll compare the range and standard deviation of the ratings available to me for the connected part of the field to the same for these separately. That may give us an estimate for the cost of playing non-1A opponents and playing extra conference games.

© Copyright 2020, Paul Kislanko
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