From an historical perspective, this battle followed immediately on from a previous action on the near side of river you see in the picture, over and around a ridge line just off the near edge of the map (see Sengoku Interlude for the historical background, and the battle). Following that action, the army of Tokugawa forced its way across the river to be once more brought to battle by the Osaka Clan.
Army Tokugawa:
1 Mounted Samurai unit @ 3SP (Strength Points) Elite1 Mounted Samurai unit @3SP Average
2 Foot Samurai @ 4SP Elite (close combat weapons only)
2 Ashigaru Yari (Spear) @3SP Avg
2 Ashigaru Yari @3SP Poor
2 Ashigaru Tepo (Shot) @2SP Avg
1 Ashigaru Yumi (Bow) @2SP Avg
Army Command Tadamasa (with elite mounted samurai)
Sub-command Tatsaki (with poor the ashigaru yari unit fording stream)
11 units + 2 Commanders => 3 Activation dice.
Total 32SP: Exhausted after minus 11SP; rout after minus 16SP.
Army Osaka:
1 Mounted Samurai unit @3SP Elite2 Foot Samurai @4SP Elite (close combat weapons only)
2 Ashigaru Yari @3SP Avg
2 Ashigaru Yari @3SP Poor
2 Ashigaru Tepo @2SP Avg
1 Ashigaru Yumi @2SP Avg
Army Command Sanada (with mounted samurai)
Sub-command Susukida (with foot samurai on left flank)
10 units + 2 commanders => 3 activation dice.
Total 29SP: Exhausted after minus 10SP; routed after minus 15SP.
A glance at the leading picture will reveal that winning the initiative roll did Tokugawa's army no good; a completely woeful score for activations. The number of units to be activated is the dice score divided by two, remainders ignored. Well, he could have done worse, but two units out of 11 to move, and the whole army not yet up, the most sensible course seemed to me to bring some of the laggard units into line.
Luck came at least partially to the aid of the yellow flags: a fine activation roll bringing 7 units into the action. Tokugawa was able to bring on a general battle all along the front line. This was helped by winning the next initiative roll, which, with activations for 5 units, seemed to indicate matters were going well for Tokugawa.
Losses had indeed been fairly heavy on both sides. So far, Tokugawa was enjoying the greater success on their left, at this point having knocked off 2SP from their opponents at no loss to themselves. The main battle, however, was going less well. Osaka had to mourn the loss of two further SPs, but Tokugawa had by now lost 5.
Fortunately Tadamasa could now call up the second unit of mounted samurai towards the main action (though he might instead have reinforced what success the Tokugawa army had so far enjoyed, to push on the left).
For their part, Osaka were inclined to leave the isolated pair of units on the right to look after themselves whilst the main army concentrated upon the foes to their front. In their own activation roll, 4 out of 5 points available went to this front. One of those went to the private battle far out to the Osaka left between the respective bow units.
However one activation point was spared to bring forward the foot samurai on the right to engage against the odds the Tokugawa left.
Tokugawa's activation roll - 9/2 -> 4 units, was spent mostly in engaging the enemy, and was successful in driving them back in the centre, but without doing much real harm.
Then the effort to wrest the initiative came to something of a lull on both sides, Tokugawa managing to activate just three units. At this point the situation was becoming rather worrying for the Tokugawa army, having by now lost 7SP - 4 of them from units destroyed - to just the 4 from Osaka. One of the two destroyed units was the the unlucky bowmen on the right, freeing up the Osaka unit that defeated them. None of the Osaka units had yet been destroyed.
On the other hand, the Green activation roll turned out to be equally dismal. Their line had been pushed back a little, and could not have been easy to restore...
Tokugawa were certainly getting much the worse of the fight, as losses continued to mount. Outmatched by their Osaka adversaries, they had by now lost 12 SPs. The exhaustion point reached, there could be no further attempt to assault the Osaka line. For their part, Osaka's losses were barely half their foes', and they were determined to push their victory home.
Their retreat towards the river was, however foredoomed. With little enough to do but watch their defeated foes retreat into the distance, Sanada's mounted samurai fetched a hook into the arquebusiers' rear, whilst the foot samurai returned to the frontal attack. The final few pictures tell the story. The surrounded ashigaru even managed to knock holes in the mounted samurai unit (Sanada himself remaining uninjured).
The isolated Samurai on the other flank soon also broke off the action, though their way back to the army, cut off as they were from the river crossings, might have been problematical.
The final action of the day found Osaka samurai catching up with an ashigaru unit holding the east-most river crossing, and, at some cost to itself, putting a quick end to it. Thereafter, the remains of the Tokugawa army made off as bets it could.
This was a resounding victory for Osaka - as unexpected as it was decisive. Fifteen SPs the Tokugawa lost,1SP short of routing. Four units were destroyed. Osaka lost 10SP - and not a single unit destroyed. In a campaign, this would amount to a disaster for Tokugawa Ieyasu.
This was one battle in which the initiative swung back and forth, both sides getting a fair share of two-in-a-row moves. Possibly the damage was done when Tokugawa's first activation roll was so miserable, and there was at least one other occasion when a mediocre roll left Tokugawa, with plenty to do, lacking the resources to do them. That the first initiative roll went Osaka's way, following a superb score in response to Tokugawa's opening, perhaps already the latter was reading the 'epimural' script.
Just a reminder of how activation rolls are determined, I have modified (very) slightly the system in the Portable Pike and Shot book. Permitting one general - excluding army command - for each whole multiple of 6 units, both armies received 2 activation dice for the 2 generals allowed to both armies. A further activation dice was allowed for each whole multiple of 6 units. As both armies fell short of the whole dozen of units (generals don't count as units) both received one more only. Both therefore received just 3 activation dice.
As it turned out, as no generals were lost, and not quite enough on the Tokugawa side to bring them down to fewer than 6 units, neither side suffered an attenuation of their available activation dice.
Altogether, this was probably the most exciting Sengoku battle of my series to date.