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NSB AI Engine for League-Supported Teams

COMPUTER MANAGEMENT LEVELS

NSB offers four levels of computer management: Traditional, Competitive, Ambitious, and Expert. Each higher level expands the computer's decision-making responsibilities. These levels affect management decisions, not player ratings or the rules governing game outcomes.

LEVEL 0 - TRADITIONAL
Established NSB computer management

Traditional uses NSB's original routines for drafting, roster moves, lineups, pitching rotations, and managerial decisions. It provides the familiar management approach used in earlier versions of NSB and remains the fallback when an advanced routine cannot complete a decision. This level is prejudiced in favor of live owners. League-Owned teams do not complete for the very best players. Rosters are managed with the aim of keeping the team viable and modestly competitive.  

LEVEL 1 - COMPETITIVE
Personnel decisions guided by team needs

Competitive adds a more thorough review of the roster. It evaluates reserve promotions, waiver candidates, and potential releases by considering positional coverage, available pitching workload, player quality, and roster space.

Reserve decisions address both immediate needs, such as injury coverage, and opportunities to improve the team over a longer period. Waiver candidates are compared with the current roster and available reserve options.

Competitive also improves draft selections and screens trades to protect valuable players and preserve adequate roster coverage. It allows mutually beneficial deals and can accept a more generous exchange than the higher levels when the team still benefits.

Lineups, rotations, and game management continue to use the established NSB routines.

LEVEL 2 - AMBITIOUS
Greater emphasis on talent and value

Ambitious builds on Competitive with more demanding trade standards and a stronger emphasis on acquiring superior talent. It gives greater weight to meaningful quality upgrades while protecting valuable team assets.

Draft selections emphasize the best available players. Exceptional waiver talent may justify an acquisition even when the team has no immediate shortage at that position.

Team needs still matter. Positional coverage, pitching workload, roster flexibility, and the consequences of losing an outgoing player remain part of the evaluation.

Like Competitive, Ambitious concentrates on personnel decisions. The established NSB routines continue to handle lineups, rotations, and game management.

LEVEL 3 - EXPERT
Personnel management plus field management

Expert includes the personnel policies of Ambitious and adds control over rotations, starting-pitcher selection, daily lineups, batting order, and player-management settings for League Owned and Computer Manager teams.

Pitching rotations continue across simulation events. Decisions consider pitcher quality, recovery, workload pace, and the upcoming schedule rather than the length of the current event.

Daily lineups consider offense, defense, handedness, park context, player availability, and playing-time needs.

Expert also sets preferences for pinch hitting, defensive substitutions, pitching changes, workload limits, bullpen roles, baserunning, and bunting. The simulator uses those preferences when making individual game-situation decisions.

Safeguards address certain defensive-availability problems and retain the established lineup routine as a fallback.

PERSONNEL MANAGEMENT AT LEVELS 1-3

Reserves
Evaluate injury replacements and strategic upgrades, choose appropriate promotion terms, and submit requests through the normal reserve system.

Waivers
Compare available players with the active roster and reserve alternatives, then submit qualifying claims through the normal waiver process. Potential releases are evaluated, but standalone AI waiver releases are not currently executed.

Trades
Evaluate incoming and outgoing talent, team coverage, pitching workload, player quality, and overall value. The goal is to improve the team while allowing trades that benefit both clubs.

Draft
Improve initial draft selections while retaining cards that remain usable in later draft iterations. Post-draft surplus trimming is subject to roster safeguards.

HOW THE LEVELS WORK

The levels are cumulative. Competitive adds personnel evaluation to Traditional. Ambitious strengthens the talent and value policies of Competitive. Expert adds field management to the personnel policies of Ambitious.

All levels remain subject to league transaction windows, roster restrictions, and existing execution rules.

Higher levels provide more extensive decision-making, not player-rating bonuses or a guarantee of winning.

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Poison Tournament Rules and Policies

Poison tournaments are a form of "Baseball Darwinism." The strong get stronger and the weak get weaker. Owners must manage changing rosters as players come and go.

Definitions

Player Exchange: An exchange of personnel (usually position for position, e.g., SP for SP) initiated by the winning team, which seeks to grow stronger by sending off a player of lesser-quality in exchange for a player of higher-quality. We can think of the exchange as a form of theft, i.e., stealing a player of better quality and shipping out the player of lesser quality. Player exchanges are sim-determined based on the sim's understanding of player quality (specifically it is based on the PV, or player value, for the random season assigned to a player when the tournament begins, not on current sim statistics/performance). 

Poison Pitcher: Anytime a poison team sends away a pitcher, that pitcher has poison status such that. Any subsequent win by that pitcher results in a player exchange benefitting his team.  

Poison Team: refers to the status of a given team, specifically, the granted authority to a a team to initiate a player exchange every time they win a game. 

Non-Poison Team: refers to the status of a team without poison status. Non poison teams initiate player exchanges only when they either (a) shut out the opposition, or (b) when a poison pitcher (if they own one) gets a win.  

Rules

1. Each tournament has either 2 or 4 "poison" teams at the start of the tournament. These teams are run by the sim, without owners, and carry a special cross symbol to identify themselves.  
2. Poison teams will exchange a player with you if you lose to them.
3. If you beat a poison team no exchange takes place, unless you shut them out, in which case your team initiates an exchange AND steals their poison status.
4. Shutouts always initiate a player exchange.
5. Poison teams can initiate player exchanges simply by beating the opposition. Non-poison teams must shut out the opposition to initiate an exchange.
6. The winning team will forego an exchange if they conclude that they cannot improve themselves by an exchange.
7. If your team receives a pitcher from a poison team, that pitcher becomes poison. If subsequently credited with a win, that initiates a player exchange.
8. Teams can become double and triple poison. This does not add to their power. Rather it simply insulates their poison status. 
9. Tournaments last only 30 games: two divisions of eight teams each with a 7-game championship between division winners.
10. Games last no more than 11 innings. A tie is declared if teams are still tied after 11 innings.
11. For competitive challenge, rosters are small - usually 14 batters and 13 pitchers. 13. Exchanges carry over into the championship series.

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Why Splits Matter in Nostalgia Sim Baseball

This article is not intended as a comprehensive explanation of splits. We assume basic knowledge of splits and how they function in the game of baseball. This article deals with the more problematic aspects of approaching split stats when data is missing. Nevertheless, some knowledge of why splits matter in the sim is integral to gaining that often-elusive "managerial edge."

The Elusive "Managerial Edge"

Whether a player's performance in Left/Right situations is truly linked to the skill set of the batter and pitcher is unclear when the sample size is small. And splits may reverse trend from season to season. It's common to see a batter do better against lefties one season and a reversal in the following season.  Yet, over the course of a career what looks like haphazard flip-flopping settles into a longitudinal trend. We can expect lefty-lefty and righty-righty matchups to be tougher on batters because those trends endure through time.  Because our sim makes split stats an integral part of sim, managers can utilize these trends to their advantage. Some things to consider:

• The more extreme a player's variation in Home/Road or Left/Right situations, the more he can be utilized to your advantage. A pitcher that is much better at home than on the road, can be given a disproportional number of starts at home to provide an advantage. 
• Lineups can be created according to Rome/Road and Left/Right splits to maximize these advantages on a regular basis.
• A left-handed batter who hits well against lefties or a right-handed pitcher who does better against left-handed batters (i.e., breaks the mold) is likely more valuable than their raw monetary value shows. 

Our sim keeps a cumulative record of a players situational performances in the so-called sim database. That data can be researched and studied prior to drafts, trades, and waiver acquisitions, to maximize the effectiveness of your team in your ballpark. 

By using the dropdown controls in the Sim Drilldown Tab of the Database, one can research long-term trends on player stats. Seasonal historical splits can be viewed on the Hitting Splits and Pitching Splits tabs (same window).    

Splits in Negro League Player Records

Stat splits are available for Negro League Players from 1936-1948. Home/Road stats are complete. Left/Right stats are partial, but we use previously-developed NSB algorithms to model/project these partials to realistic full-season scenarios. Home/road stats for the Negro Leagues introduce a new challenge to our game because so many games were of the "barnstorming" type, i.e., games played at parks across the country where one side would be arbitrarily selected as the "home" team. For this reason, we have researched the primary site for a player's "home" games and the percentage of play at that venue. This allows us to make realistic park adjustments to player stats. This data is shown on the splits tabs in the database. Behind this seemingly small enhancement lies an ambitious set of coding initiatives to determine ball park factors for the many, many parks where Negro League games were played. These factors are shown on the home split side of the database displays (see image below). As research unfolds, we will be able to further refine park factors and player stats for the years 1920 - 1935. The work is ongoing.

Thanks to the work of Retrosheet, we are able to add exhibition games, all-star games, and playoff games to the regular season games to produce a more rounded picture of performances. This now means that, unlike all other leagues, Negro League Players are not in “sealed” league universes. While this presents simulation challenges, we have decided that more data is better data for Negro League players since the data is sparse to begin with. 

In the screen sample below, Josh Gibson's Home record shows his primary home site. Since many games were barnstormed or played in neutral parks where one team was arbitrarily selected as the "home" team, to get an accurate home park effect we must consider the primary site, the percentage of home plate appearances that took place place there, and work that into the overall probability structure. This differs from how we treat most other players, who almost always played the vast majority of their home games in the same park.

Handling Split Data when it's Incomplete

This section was written in response to a policy change of August 2016. Though useful information about all stat splits can be found here, it focuses on the way the sim handles left/right matchups when only partial split data is available.

Probabilities for batter-pitcher matchups are exceedingly complex. To get the best set of probabilities it is important for a sim to create a baseline series of probabilities taking into consideration players’ relative strength compared to the leagues and seasons they actually played in, the ballpark in which the game is taking place, play-fatigue, and a few other game-time conditions (e.g., whether the infield in in or deep, whether lines are being guarded, etc.)

On top of this baseline another complex set of formulas is used to asses the situational context (i.e., batting and pitching splits) in which batter-pitcher matchups take place. There are four main situational contexts used by Nostalgia Sim Baseball:

• The handedness of the batter and the pitcher (LHB v LHP, LHB v RHP, RHB v LHP, RHB v RHP)
• The location of the matchup (HOME v ROAD)
• The state of baserunners (BASES EMPTY v ON BASE)
• Whether the batter is pinch hitting

However, these sets of conditions are not weighted equally. #1 is weighted more heavily than #2, and #2 is weighted more heavily than #3. In fact, #3 is called upon only to determine the chance of a batter getting a walk. #4 is weighted as heavily as #1, although if a pinch hitter exceeds his actual pinch plate appearances then probabilities regress to his performance mean.

Before August 2016, the sim would only use split data from seasons where all split data was complete. From 1973 on, all split data is complete. Before 1973 there are increasing numbers of games missing from the data record, making it less reliable, although there are complete data sets before 1973 in a number or cases, and the research work continues over at Retrosheet. It’s much easier to get complete data for home/road splits than for left/right splits, because the former can be garnered from box score analysis.

Effective August 2016, however, a major initiative was completed to make our sim conducive to using whatever partial left/right split data we have. To do this well required lots of retrofitting, but we are pleased with the results. And we want to share with you how we did it so that there are no mysteries in your players’ performances.

Before going any further, two things:

1. Partial Left/Right Stats are published in the owner software package in the database window on the split tabs. Whenever a partial stat is in use, it is followed by an asterisk. You will also note two columns at the right headed “RPL” and “PERF”. These indicate the percentage of real play (RPL) represented in the split–the higher the percentage the more accurate the data–and the performance level (PERF) as a factor (.98 or 1.03 etc.) of the player’s total performance.

2. Remember that the nature of probabilities is often different than we suppose. To see the real effects of splits work themselves out, many thousands of plate appearances may be required. In any given simulated season, performance can vary quite wildly. So, just because Ken Caminiti his .230 against lefties and .265 against righties in 1998, it does not guarantee that he will hit better against righties if he plays on your team. If he plays for you, he will be facing different pitchers in different parks under the direction of different managers. But let’s say that over a period of 12 months Caminiti’s 1998 season was played 10-15 times across the NSB system. With that sample size we would begin to see the larger probabilities play themselves out. Probabilities are always potential outcomes, not certain outcomes.

Now, the big problem we faced in introducing partial splits was how to keep from unfairly prejudicing performance (positive or negative). For example, look at the following stats for Fred Schulte in the 1929 season.

In 1929 we have managed to get 78.5% of Schulte’s left/right plate appearances. In those appearances, he performed worse than he did overall for 1929. If we allow Schulte’s left/right probabilities to be determined by this data, truthful though it is, we would be using left/right data to his disadvantage.

So, to correct this, we must create a profile of the remaining 21.5% of his left/right appearances using what we know about the broader tendencies of matchups. When we do this, we get the following adjustments to the left and right sides:

These adjusted numbers match up exactly to Schulte’s total AB,H,BB,2B,3B,and HRs for the 1929 season. We can’t be certain this is the actual 1929 result, but we have created a model profile with a PERF factor now at 1.00. Schulte will now not be penalized for using his left-right splits. We do the same, naturally, for pitchers.

What is Career Mode?

Career mode refers to a player’s career historical stat line deployed to create probabilities at game-time in the sim. The original NSB concept featured only itemized seasons for players, randomized anew with each new season, in order to simulate the ups and downs of player performance across the span of their careers. Beginning with Version 7.0, it is possible to draft a player in career mode (CAR for short) and use the CAR stat line for the duration of their contracted term. CAR mode comes with benefits and risks, and it’s wise to understand them before deciding when to use it. We’ll get to that, but first let’s see how CAR works by looking at a typical player stat set in the Database Window.

In this first example you see 3 stat lines for the pitcher: 1928, 1929, 1930. Below them, shaded in gray, is the Career (CAR) stat line. This line is a weighted representation of the pitcher’s career stats set to a standard, in this case 225 Innings Pitched. The 225 IP standard ensures that you can use this pitcher up to 225 IP (plus the usual 5% leeway) or so without incurring the RPL penalty for overuse.

Note: ‘’Pitchers used primarily in relief have their CAR lines set to a standard of 75 IP instead of 225 IP’’.

It’s important to know how this stat line is created, so observe now Example 2.

By expanding the selection to include ALL seasons (note the highlighted button) we can see that this pitcher also pitched a little in 1932. In regular mode, the 1932 stats are never drawn upon at game time. You would get either the 1928, 1929, or 1930 season when the pitcher was randomized. In CAR mode, however, all the historical stats matter, and they affect performance. So, it’s important to know what’s “under the hood” so to speak.

The salary of a player also changes in CAR mode. If we scroll over to the far right of the screen we see the career PV (total player value), the amount on which his contracted salary will be based. This figure is not a simple average of seasonal player values but rather an assessment of the player’s relative career worth set to 225 IP.

CAR mode adds a little more complexity to player research and drafting, but ultimately makes our sim more flexible.

What Should I Consider Before Using it?

• CAR mode uses splits and situational stats only if about 50% of a player’s career has splits available.
• CAR mode must be indicated on the draft card (see below). With the exception of Auxiliary Roster call-ups, the draft is the only opportunity to put a player in CAR mode.
• Once drafted a player remains in CAR mode for the duration of his contract. Contract duration is unaffected by CAR mode. For example, a player can be signed for multiple seasons, released on waivers, have his contract renegotiated or bought out, just as in regular mode.
• The CAR stat line itself does not adjust on screen when you click the adjustment buttons because, in effect, a CAR stat line removes a player from the park and seasonal norms and put him into an alternate adjustment “universe” determined at game time. While you can’t see adjustments for the CAR line you can see them for itemized seasons and this will give you a reasonably good idea how the adjustments are made.
• CAR mode can make many expensive players more affordable.
• CAR mode offers you the chance to use part-time (bench) players as starters.
• CAR mode mitigates against seasonal gyrations in performance.
• Since CAR mode uses career defensive stats, position players will typically be able to play at more positions, eliminating in many cases the need for “drag effects” when players are used out of position.
• Most importantly, in line with our commitment to full integration, CAR mode allows us to use Negro League players as full-time players and not relegate them mostly to the so-called odds and ends pools (OEB,OEP)!

How do I Put a Player in Career Mode?

Via Draft

When filling out your draft card, note the column header CAR. It’s a “hot” or clickable column and you can toggle player into career mode once he’s on your card. When in CAR mode, the ‘TM’ symbol appends to the player’s name. In the following example, Dennis Leonard has been toggled into CAR mode. When drafted, the sim will access a separate career database to generate his probabilities.

Via Auxiliary Call-Ups

You can also elect to place a player in Career Mode when you call him up from the Auxiliary Roster. After you select and sign the player to a short or long term contract, the CAR button will activate, allowing you to select CAR mode.