skogr Custom Match Engine for FM26

Overall Direction

The Custom Match Engine retains the core framework of the Original while adjustments have been made to ensure player attributes and situational decision-making exert a stronger influence on the match.

The modifications focus on four main areas:

• Adjusting shooting parameters and xG (Expected Goals) values to encourage more proactive goal-scoring scenarios.
  
• Expanding QME distribution data to ensure player attributes are reflected in match statistics with greater granularity.
  
• Adding supplementary system files to enable AI managers to judge match flow, momentum, and substitution options in a more systematic manner.
  
• Adjusting squad selection and substitution weight parameters so that elements like current ability (CA), potential ability (PA), condition, form, and youth player utilization function more distinctly.
  

In short, rather than simply being a mod designed to "force more goals," this Custom Match Engine is built to utilize player attributes and match situations across a much wider and more dynamic spectrum.

Shooting & xG (Expected Goals) Adjustments

The Custom Match Engine does not overhaul the entire calculation formula of the shooting model. Instead, it adjusts the base success probability values for specific shot types.

This approach is highly stable. It preserves the criteria the existing shot model uses to evaluate situations, while boosting values only in specific scenarios where shots were previously too weak or xG values were under-calculated.

The adjusted shot types are as follows:

• Standard shots
  
• Volleys
  
• Headers
  
• Shots blocked or obscured by defenders/vision
  
• Open goal situations
  
• Penalties
  
• Direct free kicks
  

The intentions behind these adjustments are clear:

• Standard shots and volleys are tuned to be slightly more threatening.
  
• Headers and open goal situations are reflected as more decisive chances compared to the Original.
  
• Penalties operate at a more realistic, high-success probability rate.
  
• Direct free kicks have been adjusted to revive direct scoring threats compared to the Original.
  

Crucially, the detailed sub-coefficients for shooting remain untouched; only the baseline success rates have been adjusted. Consequently, the core decision-making structure regarding shot distance, angle, and situation remains fully intact.

Expanding QME Distribution Data

The most significant change lies in the QME (Quantitative Match Event) distribution data.

The Original engine groups player abilities and attributes into relatively broad brackets to generate match statistics. The Custom Match Engine subdivides these brackets into much more granular segments.

The distribution data, which was around 3,000 entries in the Original, has been expanded to over 40,000 entries in the Custom Match Engine. This does not simply mean the file size is larger; it means the engine reads the differences between player attributes with far greater precision.

For example, players who behave similarly in the Original will now perform differently in the Custom Match Engine based on:

• Position
  
• Current Ability (CA) bracket
  
• Relevant attribute brackets
  
• Detailed action types (such as passing, pressing, tackling, crossing, headers, dribbling, etc.)
  

The ultimate goal of this adjustment is to make the performance gap between top-class players and average players much more visible on the pitch.

Impact on Match Statistics

The Custom Match Engine does not blindly boost all match statistics. Instead, different metrics scale in different directions.

Metrics related to work rate and aggressiveness have been enhanced:

• Pressing attempts & successes
  
• Tackling attempts
  
• Aerial (header) attempts
  
• Clearances & blocks
  
• Dribbles
  
• Forward passes
  
• Sprints & total distance covered
  

These areas have been adjusted to manifest more clearly when a player possesses high attributes. Consequently, quality players will be more active in matches, press more frequently, and engage in duels more aggressively.

Conversely, certain success rate metrics have been tuned down or calculated more conservatively:

• Pass completion rate
  
• Tackle success rate
  
• Certain interceptions and key passes
  

This serves as a crucial balance check. While increasing attempt frequencies and overall activity, the engine prevents every single action from being overly successful. As a result, the gameplay becomes much more active and dynamic without breaking the balance by inflating overall success rates.

Winger & Attacking Midfielder Adjustments

The Custom Match Engine specifically adjusts the involvement levels of wingers and attacking midfielders.

Left and Right Attacking Midfielders (AM L/R) are tuned to show more activity in:

• Crossing attempts & crossing quality
  
• Key passes & forward passes
  
• Overall passing involvement
  
• Central Attacking Midfielders (AM C) have been adjusted for higher passing involvement.
  

This encourages wingers and second-line attackers to create chances more proactively. Attack routes become more diverse than in the Original, making wing play and forward passing far more prominent during matches.

Crossing Balance Correction

The Custom Match Engine does not simply increase the quantity of crosses without checks.

After the initial QME expansion, certain crossing-related values ended up excessively low or deviated from the Original. To fix this, these values were recalibrated based on the Original's upper-bracket standards.

The purpose of this correction is to:

• Prevent crossing from being rendered obsolete.
  
• Ensure that players with high crossing attributes can showcase their strengths.
  
• Avoid inflating crossing success rates randomly.
  
• Maintain positional characteristics.
  

This is a post-processing balance check applied to crossing to ensure realistic gameplay.

Squad Selection & Substitution Logic Adjustments

The Custom Match Engine modifies team selection weight parameters as well.

The following elements are evaluated with greater weight compared to the Original:

• Current Ability (CA)
  
• Potential Ability (PA)
  
• Match condition
  
• Recent form
  
• Youth player utilization
  
• Substitute utilization & match fitness recovery
  

These changes prompt the AI to apply more active and logical criteria when selecting starting lineups and making substitutions. For the first team, AI managers will heavily favor ability and form. For rotations or reserve-squad decisions, youth utilization and player fitness recovery are heavily weighed.

Additionally, risk factors such as impending suspensions carry heavier penalties. The AI does not just blindly field the strongest player; it evaluates squad management risks more clearly.

Role of the Newly Added QME System Files

The Custom Match Engine includes QME system definition files that are absent in the Original.

These files serve as the rulebook connecting player attributes to on-pitch decision-making.

Key objectives of these files include:

• Ensuring no player attribute is wasted or ignored in match calculations.
  
• Evaluating important attributes differently depending on position and role.
  
• Translating raw 1-20 attributes into optimized in-match calculation values.
  
• Consolidating attacking, defending, off-the-ball movement, stamina, kickoff, and goalkeeper decisions into a unified ruleset.
  
• Ensuring hidden attributes and specific personality traits exert actual influence in relevant situations.
  

For instance, this system does not simply look at "Finishing" for shot outcomes. It is designed to evaluate decisions, composure, off-the-ball movement, physical context, and situational pressure collectively.

These files are essential to the core philosophy of the Custom Match Engine. To utilize player attributes on a wider scale and let diverse attributes influence outcomes dynamically, the default distribution data alone is insufficient. This is why the QME calculation principles and role-based attribute translations have been defined in a separate system.

Key Refinements in the QME System

These added QME system files are not just documentation; they represent the actual engine configurations.

Key details include:

• The evaluation range for finishing-related attributes has been expanded.
  
• Shooting bonuses are applied more strongly than before.
  
• Environmental conditions (stamina, weather, pitch state) are mapped to affect the specific attributes they naturally influence, rather than being locked to a single parameter.
  
• Attribute aliases have been added to bridge mismatches between role-based attribute names and actual runtime attribute variables.
  
• Momentum data references have been corrected to match the actual distributed filenames.
  

These refinements reduce the occurrence of "broken links" where data exists but fails to resolve in calculations. This ensures that the developer's intended attribute-use logic flows consistently through runtime match calculations.

Role of the Momentum-Based Decision-Making System

Another additional file is the momentum-based decision-making system.

This file structures the factors that AI managers evaluate during matches.

Included decision factors are:

• Manager tendencies/personality
  
• Current match situation
  
• Current tactical status
  
• Opposition tactical analysis
  
• Match momentum
  
• Tactical instruction options
  
• Substitution options
  

Crucially, this system does not force the AI to use a specific preset tactic.

Instead, it presents options, analyzes the situation, and links reference data. The final choice of when to adjust, which sub to make, and what instruction to change is left entirely to the AI manager's logic.

Thus, the goal of this system is not to force specific tactical behaviors on the AI, but to enable the AI to read the match flow and consider a wider array of options.

Why These Additional Files Are Necessary

The Custom Match Engine is not a simple tweak of numbers.

When you expand the QME distribution, you need a philosophy on how to interpret that distribution. If you adjust xG, you must define the system in which shooting decisions and finishing bonuses operate. If you want the AI to make active substitutions and tactical shifts, you must structure the data and decision flows they reference.

Thus, the roles of these files are as follows:

• QME System File: The rulebook connecting player attributes to match events.
  
• Momentum Decision System File: The analytical system providing options to help AI managers make in-match decisions.
  

These two files provide the foundation for the Custom Match Engine. They were added to fully realize the developer's goal of creating a "more attribute-driven, situation-responsive, and AI-advanced match engine."

Unchanged Areas

The Custom Match Engine does not change every single file.

The following areas are confirmed to be identical to the Original or remain unchanged in comparisons:

• Tactic presets
  
• Physics parameters
  
• Match rating (player rating) calculation data
  
• OOP (Out of Possession) scoring parameters
  
• Original baseline momentum weights
  
• Positional attribute weight mappings
  

The Custom Match Engine does not overturn the physics engine or preset tactical systems; rather, it refines match decisions, statistics generation, expected goal logic, and AI selection criteria.

Summary

This Custom Match Engine is designed to ensure player attributes translate much more distinctively into on-pitch actions.

Quality players will move more, press more, and create chances more aggressively, with shooting situations yielding more realistic, threatening results. Involvements from wing play and the second line are boosted, making the overall flow of the match more dynamic.

However, success rates are not blindly inflated. Certain metrics like pass completion and tackle success are tuned conservatively to keep the game balanced—meaning players will attempt more, but actions will not succeed too easily.

The newly introduced system files support this direction: one is the QME system rulebook that dynamically maps attributes to gameplay, and the other is a decision-making assistant that enables AI managers to react to match momentum.

In summary, this engine aims to deliver "more active play, visible attribute differences, and richer AI decision-making."


Except for the match_events.xml file, the previous vanilla engine is identical to the 26.3.1 original engine.
Applied the modified match_events.xml file from version 26.3.1 to the custom match engine

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May 29, 2026 Update

Goal of the Update

This update to the Custom Match Engine aims to resolve issues where defenders and goalkeepers react too slowly or position themselves poorly during shooting situations inside the penalty box.

In the default settings, defenders tended to initiate blocks only after detecting a shooting motion, while goalkeepers leaned heavily towards covering the near post during angled shots. This often resulted in defenders failing to press a ball-carrier who was already in a shooting position, or goalkeepers getting caught off-balance (wrong-footed) after over-committing to the near post.

First Modification: Reacting to the Ball-Carrier Inside the Box
The first adjustment shifts the trigger from "reacting after detecting a shooting motion" to "reacting the moment the opponent gains possession inside the penalty box."

Defenders are now configured to have the nearest player immediately press and block the shooting lane if the ball-carrier inside the box has a shooting angle. If there is not enough time to close down, they will attempt standing blocks, body blocks, or diving blocks.
To prevent block attempts from being suppressed due to penalty risks, defensive actions are not completely restricted. Heavy direct tackles on the ball-carrier, late sliding tackles, and tackles making contact from the back or side first are restricted. In contrast, actions that strictly block the shooting path are permitted.
The goalkeeper's logic has been aligned with this change as well. If a ball-carrier inside the box creates a shooting angle, instead of waiting passively in a set position, the keeper will close down the angle, move forward if necessary to smother the ball, or perform reactive saves.
Second Modification: Resolving Near-Post Over-commitment
The second adjustment addresses the goalkeeper's tendency to over-commit to the near post during angled shots.

Previously, goalkeepers were configured to prioritize covering the near post first. This caused them to move towards the near post prematurely rather than positioning themselves relative to the shooter and the entire goal. Consequently, if the ball went straight at them or towards the far post, they were often wrong-footed due to their weight already shifting in one direction.
In this update, the near-post priority command has been removed. The goalkeeper now positions themselves based on the bisector of the shooting angle formed by the shooter, the near post, and the far post. This means the keeper will block the near post using their body positioning while keeping the far post within diving range.
During angled shots, the keeper remains balanced in the center of the shooting cone rather than drifting too close to the goal line or near post. Even if the shot comes straight at the keeper, they will maintain forward balance and attack the ball rather than backing off or leaning to one side.
Summary
The core of this modification lies in two key areas:

Inside the penalty box, defenders and goalkeepers now react the moment the opponent controls the ball and creates a shooting angle, rather than waiting for the shot to be released.
The goalkeeper no longer over-prioritizes the near post. Instead, they position themselves logically based on the shooter and both posts, reducing instances of over-committing to the near post during angled shots or getting wrong-footed on central shots.

Version 26.3.2 was not updated because the file contents are identical to version 26.3.1.

How to install this FM26 Custom Match Engine

Locate your game installation folder.

Go to the \Football Manager 26\shared\data\ folder and make a backup of the original simatch.fmf file.

Extract the downloaded zip file and place the contents into the folder.

Support & Credits

Support my work by buying me a coffee! buymeacoffee.com/skogr

https://www.patreon.com/c/skogr