This week's featured article at the Sobel Wiki is on the Battle of Saratoga, the event that serves as the point of divergence for the Sobel Timeline.
Historically, the Battle of Saratoga was a rather drawn-out affair, lasting from the initial contact between the British and American armies on September 19, 1777 to Burgoyne's final surrender on October 17 (or, in the Sobel Timeline, Burgoyne's final victory on October 25). The question naturally arises, then: when, during that period, did the actual point of divergence take place, and what was it?
Here's Sobel, pp. 30-31: "Burgyone attacked on on September 18, but was forced to retreat before Gates' withering fire. Then the Army of Nations advanced toward Freeman's Farm, and once again was repulsed. Decimated and battered, the Army of Nations regrouped to hear Burgoyne's plan. Caution would have dictated retreat into the woods, but he held fast.
"Awakening on the morning of October 8, Burgoyne learned his force was all but surrounded, and would have to fight its way out of a cordon of rebels. Still morale held. As one survivor later wrote, 'The men were willing and ready to face any danger, when led by officers whom they loved and respected and who shared with them in every toil and hardship.'
"Rallying his men, Burgoyne took them to Schuyler's Farm, and the next morning crossed the Fishkill River. Had Gates attacked then, he could have destroyed the Army of Nations. But he hesitated at that crucial moment, spending his time arguing with Arnold, regrouping his forces, and considering his next move. Meanwhile, unknown to the rebels, Clinton's force moved swiftly up the Hudson, and prepared to attack Gates from the rear. Time was working for the British. Burgoyne knew this; Gates did not.
"On October 13, Burgoyne sent a delegation to ask Gates his terms for a truce. The answer was 'unconditional surrender.' Burgoyne replied that he was not unwilling to admit defeat, but insisted his men be allowed to march from the field with all honors. Gates wavered; he wanted the satisfaction of receiving Burgoyne's sword on the field of battle. At the time Gates had ambitions to succeed Washington, who was in bad grace in Philadelphia. Such a victory, conceded on the field, would assure him of supreme command.
"As Gates hesitated, Clinton's force smashed Israel Putnam's rebel army and continued toward Saratoga. Putnam sent messengers with news of his defeat to Gates, but the men were lost in the woods, and never appeared at headquarters. By the time Gates learned of Clinton's imminent appearance, it was too late to do much about it. The rebel general was now obliged to act in an impromptu fashion. His plan was simple. The rebels would attack Burgoyne's position in force, massacring all, and then turn to face Clinton's army, which was expected in a matter of hours.
"The attack came on the morning of October 21. Wave upon wave of rebels advanced on the weakened Army of Nations, and each time they were repulsed. Then, on October 22, Clinton's men broke through Gates' rear."
Historically, after the battle of Freeman's Farm on September 19, Burgyone was considering making another attack on the Americans. However, he received word of Clinton's planned advance up the Hudson to Albany, and chose to sit tight and wait until word reached him that Clinton was near. When he wrote Burgoyne on September 12, Clinton had anticipated launching his attack in ten days. However, it was not until October 3, three weeks after sending his message, that Clinton began his move up the Hudson. Clinton was able to force Putnam to withdraw due to a well-conducted feint, then took Forts Montgomery and Clinton on October 6, leaving the way clear to continue north up the Hudson. Clinton then fell ill, and returned to New York City, leaving General John Vaughan in charge. Clinton ordered Vaughan to "proceed up Hudson's river, to feel for General Burgoyne, to assist his operations", but Vaughan was delayed, and didn't set out until October 15. On October 17, Clinton received orders from General Howe to send 3000 men to support the occupation of Philadelphia, and Clinton ordered Vaughan to turn back.
Meanwhile, at Saratoga, Burgoyne learned that Clinton had been delayed, and on October 3 he put his army on short rations. The next day, Burgoyne called a war council, but it was not until the 5th that he decided to attack the Americans on October 7th. The attack, known as the Battle of Bemis Heights, went badly for the British almost from the beginning, and by the time night fell the British lines had been breached and Burgyone had lost nearly 900 men.
The next day, Burgoyne began to retreat north across the Fishkill River, completing the crossing on October 10. On the 11th, he attempted to lure the Americans into a trap by sending a double agent to tell Gates that he was retreating up the river. The plan failed when a deserter from Burgoyne's army warned the Americans about the trap. On the 12th, Burgoyne and his officers agreed that they had no choice except to surrender, and on the 13th an officer came to Gates to request terms. Gates initially insisted on unconditional surrender, but soon reconsidered. Surrender terms were agreed on the 16th, and Burgoyne surrendered to Gates the following day.
Comparing Sobel with actual history, it seems as though the actual point of divergence must be Clinton setting out from New York City on schedule on September 22. Burgoyne continues to act as he did in our history, retreating north across the Fishkill River on October 9. Sobel doesn't mention the Battle of Bemis Heights, which might mean that it never took place. However, based on Burgoyne's retreat across the Fishkill, it seems likely that it did take place and Sobel simply chose not to mention it. By the time Burgoyne is offering to negotiate his surrender to Gates on October 13, as he did in our history, Clinton is closing in on Albany, and "smashes" an American army under Israel Putnam. Burgoyne by this time has received word of Clinton's approach, and instead of surrendering, he continues to sit tight. When Gates attacks on October 21, Burgoyne is able to drive him off, then attack in his turn the next day after Clinton attacks Gates from behind:
"Heartened by the sound of their comrades' bullets, Burgoyne's ragged force, now numbering less than 2,000, staged its final assault, in this way placing the now-panicky rebels in the jaws of a pincer movement. It was now Gates' turn to flee, and so he did. Within two days the rebels were on the outskirts of Albany, vulnerable to attack, unable to respond. On the afternoon of October 25, Burgoyne offered Gates a generous peace. All his troops could return to their homes, while Gates himself would be free to leave, upon his pledge never to fight again. The proposal was accepted; Gates had no choice but to do so. So ended one of the most glorious episodes in the history of eighteenth century warfare."