if ((navi.BaseHP / 10) > battle.Level)
	Odds: 1
else if (1.5 * (navi.BaseHP / 10) >= battle.Level)
	Odds: 13/16, 13/16, 15/16
else if (2 * (navi.BaseHP / 10) >= battle.Level)
	Odds: 10/16, 10/16, 15/16
else
	Odds: 6/16, 6/16, 15/16
After multiplication or division, round down.

In-battle run rates:
100% run:	100%
81.25% run:	81.25%, 81.25%, 93.75%
62.5% run:	62.5%, 62.5%, 93.75%
37.5% run:	37.5%, 37.5%, 93.75%
Note: your run % is always 93.75% from the third try onwards.

threshold:	value * 10
100% run:	HP >= threshold + 1
81.25% run:	HP >= threshold * 2/3
62.5% run:	HP >= threshold * 1/2
After multiplication, round down to the nearest multiple of 10.

HP table: you need at least this base HP to get the specified run rates. Accounts for integer rounding.

			value		threshold	100% run	81.25% run	62.5% run
Principal's PC 1	20		200		220		140		100
Principal's PC 2	20		200		220		140		100

Zoo Comp 1		30		300		320		200		160
Zoo Comp 2		30		300		320		200		160
Zoo Comp 3		30		300		320		200		160
Zoo Comp 4		30		300		320		200		160

Hospital Comp 1		55		550		560		380		280
Hospital Comp 2		55		550		560		380		280
Hospital Comp 3		55		550		560		380		280
Hospital Comp 4		55		550		560		380		280
Hospital Comp 5		55		550		560		380		280

WWW Comp 1		80		800		820		540		400
WWW Comp 2		80		800		820		540		400
WWW Comp 3		80		800		820		540		400
WWW Comp 4		80		800		820		540		400
Alpha			90		900		920		600		460

Lan's HP		-		-		-		-		-
Mayl's HP		15		150		160		100		80
Dex's HP		20		200		220		140		100
Yai's HP		20		200		220		140		100
Tamako's HP		30		300		320		200		160

EduComputer		30		300		320		200		160
Lion Comp		30		300		320		200		160
Demon Comp		50		500		520		340		260
Editing Comp		50		500		520		340		260

Doghouse Comp		10		100		120		80		60
Blackboard Comp		10		100		120		80		60
Vending Comp (SciLab)	30		300		320		200		160
Computer		20		200		220		140		100
Board Comp		20		200		220		140		100
School Server Comp	15		150		160		100		80
Relay Comp		35		350		360		240		180
NetBattle Comp		30		300		320		200		160
TV Board Comp		40		400		420		280		200
Phone Comp		20		200		220		140		100
TV Comp			65		650		660		440		340
Bed Comp		55		550		560		380		280
Vending Comp (Hospital)	55		550		560		380		280
Ticket Comp		20		200		220		140		100
Tank Comp		70		700		720		480		360
Old TV Comp		20		200		220		140		100
Armor Comp		20		200		220		140		100
Sign Comp		25		250		260		180		140
Alarm Comp		20		200		220		140		100
Door Sensor Comp	25		250		260		180		140
Wall Comp		80		800		820		540		400

ACDC 1			15		150		160		100		80
ACDC 2			15		150		160		100		80
ACDC 3			20		200		220		140		100
ACDC Square		-		-		-		-		-

SciLab 1		30		300		320		200		160
SciLab 2		30		300		320		200		160
SciLab Square		-		-		-		-		-

Yoka 1			35		350		360		240		180
Yoka 2			35		350		360		240		180
Yoka Square		-		-		-		-		-

Beach 1			40		400		420		280		200
Beach 2			40		400		420		280		200
Beach Square		-		-		-		-		-
Hades Isle		50		500		520		340		260

Undernet 1		60		600		620		400		300
Undernet 2		65		650		660		440		340
Undernet 3		70		700		720		480		360
Undernet 4		75		750		760		500		380
Undernet 5		80		800		820		540		400
Undernet 6		90		900		920		600		460
Undernet 7		100		1000		1020		680		500
Under Square		-		-		-		-		-

Secret 1		120		1200		1220		800		600
Secret 2		120		1200		1220		800		600
Secret 3		120		1200		1220		800		600

Some areas have rare battles with weaker viruses that are easier to get away from. They are the following:
			amount		value		threshold	100% run	81.25% run	62.5% run
Dex's HP		1/8		16		160		180		120		80
Vending Comp		6/8		20		200		220		140		100
Armor Comp		4/8		10		100		120		80		60
Alarm Comp		3/8		10		100		120		80		60
Door Sensor Comp	8/11		20		200		220		140		100