//------------------------------//
// How About a Nice Game of Chess? 
// Story: Starlight and Sunburst's Misadventures in Creating Artificial Intelligence 
// by Golden Tassel 
//------------------------------//

"This is a bad idea," Sunburst said. "The AC is going to lose!"

"It's your idea," Starlight reminded him. "You said yourself we need to find somepony who's good at chess to properly test our new spell." She raised the AC in her turquoise aura, admiring the glint of sunlight off its smooth faces. "Where better than here?" she asked, waving her hoof at the row of stone tables before them in the park where a dozen ponies were already gathered, playing friendly games of chess against each other.

"Yes, eventually. But we haven't worked out all the kinks yet. I still haven't figured out how to solve its problem with the en passant rule, and—more importantly—what if the telekinesis glitch happens again? Somepony could get hurt!" Sunburst winced as he absently rubbed his shoulder.

"We fixed that! Don't worry. And we'll just have to hope that the on pass-whatever thing doesn't come up." Starlight dismissed his concerns with a wave of her hoof.

Sunburst glanced quickly across the row of tables. "It looks like there aren't any open spots. Oh well. We'll just have to come back later." He grabbed for the AC with his magic while turning to leave.

"Somepony just got up! Come on," Starlight said, trotting out to claim the vacant seat. She kept a strong grip on the AC in her aura and Sunburst found himself dragged along with it by his horn.

An older earth pony stallion with a red coat and brown mane with a few streaks of gray running through it was sitting on the other side of the open table. He eyed the two unicorns curiously as they approached. "Hello," he said in a thick Stalliongrad accent. "You are new here."

Starlight sat down across from him and placed the AC on the table. "Yes, it's our first time. My name is Starlight Glimmer, and this is Sunburst," she said, motioning to her friend who was anxiously hovering over her shoulder.

"Kanterov," the stallion introduced himself. "What is this?" he pointed to the AC.

Starlight put on a broad smile. "This is an Arcane Computer, and it's why we're here. You see, we've been experimenting with creating a spell that can play chess by itself, and we were hoping to find somepony to help us test it. How good are you at chess?"

Kanterov snorted, holding back a chuckle. "I am rated twenty-eight-hundred." He leaned forward as he started setting up the board, giving himself the black pieces.

Starlight glanced at Sunburst who just shrugged. "Is that good?" she asked cautiously.

"Is good." Kanterov smirked. "Show me what magic box do."

Starlight cast the activation spell and the cube lit up with its own crimson aura. An illusion spell displayed a small blue circle in the air above it, and a bright band began spinning around it slowly. After a few seconds the king's pawn lifted up in its crimson grasp and moved two squares forward.

Kanterov quickly responded by pushing a pawn out two squares in front of his queen's bishop and recorded the opening moves on a fresh sheet in his notepad: 1. e4 c5. "This my favored opening," he said while leaning back for a stretch. "This does not bode well for—" He sat up straight as he saw the AC play the uncommon move c3, advancing a pawn to where it would soon disrupt his preferred sequence of moves. Furrowing his brow, he responded by pushing his queen's pawn to d5, where it was immediately captured by the AC's king's pawn, and Kanterov re-captured the pawn with his queen. He had barely written down the sequence of moves before the AC moved its queen's pawn to d4, asserting its control over the center of the board.

"I hope you are not here to make fool of me," Kanterov said as he developed his king's knight. "Some rival of mine perhaps playing remotely through your toy?" He stared intently at the spinning circle above the cube while the AC mirrored his move with its own knight.

Sunburst blurted, "I swear we have no idea who you are." He shrunk back behind Starlight as the older stallion's stare snapped to him.

"What Sunburst means is we're just here to test our spell. It beats both of us easily, but as I'm sure you can tell, we barely know how to play, so we have no idea how good it is," Starlight explained calmly.

Apparently placated, Kanterov returned his attention to the board and continued playing silently, taking a minute or two for each move as he methodically developed each of his pieces, undaunted by the AC's rapid responses. Certainly, none of his rivals would spend so little time calculating their moves against him. Near the end of the opening the AC had already castled while he had yet to do so, but he considered it acceptable since, after a trade of pawns had left the AC with an isolated queen's pawn—a weakness he knew he could exploit—he was able to clear a path to safety for his king and finish his development with an instigating move of his dark square bishop to b4, aiming through the gap in the AC's pawns.

The AC challenged the bishop by moving a pawn to a3, forcing Kanterov to retreat to a5. It didn't respond immediately after this, and Sunburst began pacing, worried that it had gotten stuck on something. He kept glancing between the board and the circle above the cube; as long as it was still spinning, the spell hadn't fizzled, and all he could do was wait. It may have taken only a minute, but it was a shockingly long minute before it finally moved its knight to c3, attacking Kanterov's queen which had sat motionless in the center of the board since the third move.

Kanterov didn't want to capture the knight, as it would cost him his bishop which he knew would be more valuable than a knight in the endgame, so his queen had to move. After taking several minutes to think, he moved it back one square to d6 and patiently considered his options for counter-play while waiting for the AC's next move.

The AC was taking longer to make its decisions now, and neither Starlight nor Sunburst knew if this was a good sign or not, though Sunburst was starting to worry if it was going to overheat again. At least the stone table wouldn't be at risk of catching fire.

When the AC decided to chase the queen by moving its knight to b5, Kanterov looked up from the board, raising an eyebrow as he locked eyes with Starlight. Was it a good move? Was he surprised by it? Afraid to ask, she just smiled.

Kanterov made an impassive grunt and returned his attention to the board. He spent a long time calculating before ultimately retreating his queen to e7. After another couple minutes of waiting, the AC moved its other knight forward to e5, taking advantage of the fact that Kanterov had still not castled by introducing a threat against his queen-side knight on c6 and simultaneously revealing an attack against his light-square bishop on h5. The knight was not an immediate problem, but the AC had both its queen and bishop lined up against his bishop which had only the king's knight to defend it. With nowhere to retreat, he was forced to exchange bishops with the AC and with the pressure momentarily relieved, he finally castled.

The AC continued its attack by moving its queen's rook to c1, adding pressure to Kanterov's knight. He was now faced with a problem: if he traded with the AC's knight, it would bring that isolated pawn into an attack against his remaining knight. Beyond that, the AC had coordinated its pieces so well that from that position it would then be able to win a pawn from him and even bring its rook forward to threaten his queen. Retreat and defend seemed to be the only moves the AC would allow him to make.

Kanterov mirrored the rook move to protect his knight and stood up to stretch his legs and take his eyes off the board for a few minutes of rest while he waited for the next move. It was at this point he realized a small crowd had gathered around his game against the unicorns' magic box. They were standing a polite distance away and keeping quiet, but he could hear them whispering speculations about the strength of his position.

"Mister Kanterov?" Starlight's voice caught his attention. "It's your move when you're ready."

He sat back at the table and took a deep breath as he took a fresh look at the board. The AC had played its dark-square bishop to g5, pinning his king-side knight to his queen. Doing this had removed a defending piece from the isolated pawn on d4, leaving only the knight on b5 to protect it. He was, however, still facing down a very aggressive position where the AC had managed to constrain his pieces to his side of the board. He had precious little room to maneuver. Kanterov needed to begin a counterattack, or he would quickly find himself with even less to work with, so he moved his bishop to b6, focusing on that weakened pawn in the center. All he had to do was win that pawn, and the game would shift in his favor.

The AC spent several minutes calculating from this position. During this time Sunburst found himself drawn aside by some of the onlookers. While the crowd was hardly interested in the AC's enchantment framework, there were many questions about how it decided which moves to play and how many moves deep it was able to calculate. Sunburst did his best to answer them without getting too technical and being careful not to mention any of the flaws he knew it still had.

That didn't stop some of the ponies in the crowd from asking questions that seemed to be aimed at finding possible flaws. As one of them, intrigued by the fact that the AC's calculations assumed its opponent would always chose the best moves it could find for them, asked, "What if Kanterov played a bad move? Wouldn't that make it think it made a mistake and that the move is actually good?"

Sunburst blinked. He knew very well from personal experience that the AC had no problem defeating bad moves. "No... It doesn't think. A bad move is a bad move and it will see it that way. You can't fake it out like that."

There was some murmuring within the crowd at that. Some of them took issue with the idea of something that couldn't think being able to play chess at all, let alone well enough to challenge Kanterov.

Then came the question Sunburst had hoped wouldn't be asked: "Is it going to win?"

Sunburst had no idea if the AC would win and, as he had come to realize how strong of a player Kanterov was, worried what it would mean if the AC could defeat him. He was stammering his way through an evasive answer when the sound of a piece being set down on the board drew everyone's attention back to the game. Sunburst breathed a sigh of relief and excused himself from the crowd, returning to Starlight's side to see what had happened.

The AC had moved its bishop to f6, capturing the knight that had been pinned there in front of Kanterov's queen. This had put him in a precarious position, but the possibility of this move had not escaped him. Kanterov knew that he couldn't recapture the bishop with his queen because the AC's king-side knight would then move to d7 to attack both his queen and the rook guarding his king; he would lose the rook. Unfortunately, this meant his only viable option was to capture with the pawn directly in front of his king, ripping open his castle.

The AC responded immediately by moving its knight to c4, getting it out from under the attack by that pawn.

Determined to press his attack against the isolated pawn in the center, Kanterov moved his king-side rook to d8. The AC followed by trading its knight for the bishop on b6, forcing him to double-up his pawns in the b-file to capture the knight.

After a minute, the AC decided to defend its weak center pawn with its king-side rook, and Kanterov responded by pushing a pawn to f5, opening up a diagonal for his queen and clamping down on the space available for the AC's queen. It moved its queen forward one square to where it aided in the defense of that pawn, and Kanterov followed suit by moving his queen onto the open diagonal, adding to his attack on the center. That single pawn was now sitting in the crosshairs of a knight, rook, and queen from both players.

And then the AC moved that pawn.

A hushed chorus of gasps and murmurs echoed through the crowd at this move, and even Kanterov appeared surprised by it. Starlight and Sunburst exchanged glances with each other, neither understanding why a simple pawn move had received such a reaction.

Kanterov knew exactly why. Up until this point, the AC had played very materialistically; it never allowed him to capture a piece without itself capturing something of equal value—pawn for pawn, bishop for bishop, bishop for knight, knight for bishop. But with this move, it had effectively sacrificed the pawn. It was a move he would have played in its position.

He won the pawn with a trade of rooks, but was now presented with a new threat from the AC: both its queen and rook were on open files that would allow it to directly attack his king. In preparation to defend himself, he moved his king into the corner on h8 and after the AC captured the undefended pawn on b6, he repositioned his rook onto g8, taking advantage of the opening in his castle to threaten the pawn directly in front of the AC's king.

The AC appeared to have returned to its materialistic behavior, moving its queen to c5 to attack another undefended pawn, seemingly unconcerned about its own king.

Kanterov advanced his pawn to d4 where his knight and queen guarded it, and the AC brought its knight to d6. Against any other opponent, Kanterov would have considered this a mobilization toward his king, but now that he had seen the greedy nature of these unicorns' bauble, he assumed this was only because it was threatening two pawns at once with this move and he continued his attack by advancing his pawn to f4, closing in on the AC's castle.

The AC confirmed his suspicions when it moved its knight again to capture his b7 pawn which was of no practical value at this point in the game. Kanterov laughed at this. "I'm not so sure you're on right track now," he admonished as he mobilized his knight to e5, seizing the opportunity to build more pressure against the AC's king.

Sunburst felt a rush of lightheadedness while Starlight bit her lip to keep from making an outburst. Neither of them could tell on their own how bad the position really was, but Kanterov's confidence told them they were about to lose.

But the AC was immune to such psychology. It knew a good move from a bad one, and it knew when victory was certain. Its queen moved to d5, guarding against a possibly dangerous check from Kanterov's knight. That didn't, however, stop him from pushing his pawn to f3 instead; a move that threatened to break the line of pawns guarding its king. Advancing a pawn to g3 maintained its defensive structure, if only barely.

Kanterov's knight pivoted to d3, threatening the AC's rook which then abandoned its king in a move to c7, coordinating with is queen in a counterattack. There was no threat of check that came with such an attack, however, and he ignored it to move his rook onto e8 with a clear path to the AC's unguarded back rank. Unless it did something to stop him, he would have checkmate in three moves.

The AC played its knight to d6, attacking the rook, but doing nothing to stop him from charging his rook across the board to attack the AC's king.

"Check," Kanterov announced calmly.

The AC had only one legal move and retreated its king into the corner. And after its f2 pawn was captured by Kanterov's knight, it was one move away from losing. But Kanterov had overlooked a fatal weakness in his position, and when the AC's knight attacked his king, his eyes widened as he realized his mistake.

A sudden quiet fell around the table. Starlight looked across at Kanterov and cautiously said, "Check."

He quickly moved his king.

The AC moved its knight, revealing another attack on the king from its looming rook.

"Ch-check," Sunburst said, feeling his heart race.

Kanterov moved his king again, but the AC pressed the attack with its rook.

"Check!" Starlight could barely restrain herself.

It was there that Kanterov, with a heavy sigh, toppled his king and stood up to reach across the table and shake hooves with Starlight and Sunburst.

The AC had won.