Analytical report for the 19th round of Segunda RFEF – Group 4, Season 2025-2026: Mathematical modeling and strategic analysis of football dynamics in Southern Spain

Description

Analytical report for the 19th round of Segunda RFEF – Group 4, Season 2025-2026: Mathematical modeling and strategic analysis of football dynamics in Southern Spain

This report presents a comprehensive statistical and mathematical review of the nine matches that make up the 19th round of the Spanish fourth division football, known as Segunda Federación – Group 4. In the context of the dynamic 2025-2026 season, this round is a key turning point in determining the positions for direct promotion, playoff quotas and the fight for survival in one of the most competitive regional groups in Spain. ¹ Using a rigorous mathematical calculation protocol based on the Poisson distribution and stability coefficients, the analysis aims to provide an objective assessment of the risks and potential outcomes for each event, considering them not simply as sporting events, but as complex mathematical relationships. ²

Geopolitical and tactical context of Segunda RFEF – Group 4

The Spanish Segunda RFEF is defined by its high intensity and strong territorial affiliation. Group 4 mainly includes teams from Andalusia, Extremadura and the autonomous city of Melilla, which introduces specific logistical and climatic variables into the success equations. By the 18th round, the league is showing an average goal… source of statistical performance – from win percentage to average goals conceded – becomes a critical input for the algorithm. ¹ Before proceeding to the detailed calculations for each match, it is necessary to consider the current standings after 18 matches played, which serves as the foundation for step 1 of our protocol. ²

Position	Team	M	P	P	H	VG	PG	GR	T
1	Aguilas FC	18	10	5	3	23	11	+12	35
2	Xerez CD	18	10	3	5	19	13	+6	33
3	UCAM Murcia	18	9	4	5	26	18	+8	31
4	Recreativo Huelva	18	8	5	5	21	14	+7	29
5	La Union	18	8	4	6	21	18	+3	28
6	Lorca Deportiva	18	8	4	6	18	15	+3	28
7	CD Extremadura	18	7	7	4	26	25	+1	28
8	Antoniano	18	8	3	7	21	19	+2	27
9	Yeclano	18	8	3	7	15	13	+2	27
10	Deportiva Minera	18	7	5	6	24	20	+4	26
11	Xerez DFC	18	6	7	5	24	21	+3	25
12	Genil Bridge	18	6	7	5	14	16	-2	25
13	Jaén	18	6	6	6	19	21	-2	24
14	Linares	18	5	8	5	20	23	-3	23
15	Melilla	18	4	9	5	17	16	+1	21
16	Almeria B	18	3	4	11	12	25	-13	13
17	CD Estepona	18	3	3	12	16	27	-11	12
18	Malaga B	18	1	3	14	10	31	-21	6

The data is synthesized from sources : ¹

Presentation of the mathematical protocol for calculations

To achieve maximum objectivity, each match is subjected to a seven-step computational process, as defined in the ‘Master_Template’. ² This approach eliminates emotional bias and focuses on probability fields generated by the teams’ historical performance.

Step 1: Calculating base percentages and averages

The first step involves deriving the frequency indices for wins ($W \% $), draws ($D\%$) and losses ($L\%$) since the beginning of the championship. For example, for a team like Xerez CD, which has 10 wins in 18 matches, $W\%$ is 55.5%. ¹ In parallel, the average number of goals scored ($GF _{ avg}$) and goals conceded ($GA_{avg}$) per match is calculated. These values serve as a “genetic code” of the team’s current form. ²

Step 2 and 3: Calculating Attack Power and Defense Power

The Attack Strength ($Atk$) in our protocol is not simply the number of goals, but an aggregate metric that includes $W\%$, $L\%$, and $GF _{ avg}$. ² The logic here is that a team with a high win-loss percentage (low draw propensity) often has a more polarized and active attack. The Defensive Strength ($Def$) formula uses the reciprocal of the win-loss difference, adjusted for goals conceded. ² This allows the model to identify teams with “fragile” defenses that crack under pressure, even if they have a decent goal difference.

Step 4 and 5: Expected Goals (xG) and Poisson Distribution

Expected goals ($xG$) are calculated by the arithmetic mean of one team’s attack and the opponent’s defense. This synergistic formula allows us to predict how two different styles of play will neutralize or reinforce each other. ² The probabilities for outcomes 1, X, and 2 are generated by the Poisson function:

$$ P( k; \lambda) = \frac{\lambda^ke^{-\lambda}}{k!}$$

where $\lambda$ is the expected value of goals ($xG$), and $k$ is the number of goals. By summing the probabilities of all possible outcomes (e.g. 1:0, 2:1, 0:0), the model derives the final percentages for win, draw, and loss. ²

Step 6 and 7: Stability, Equality and Harmony Indices

The stability of the model ($K$) measures the standard deviation of the predicted probabilities with respect to their mean. When $K$ is high, it indicates a clear differentiation between the three possible outcomes, making the prediction more reliable. ² The equality index ($L$) is critical for the Spanish lower leagues, where tactical equality is often the goal of the visiting teams. ³ The final “Harmony Index” synthesizes all these factors into a single figure that serves as a risk classification. ²

Detailed analysis of the matches from the 19th round

Match 1: Malaga B vs. CD Extremadura

Date and time: January 17, 2026, 6:00 PM.

Odds: 1: 3.53 | X: 3.33 | 2: 1.95

Malaga B (Atletico Malagueno) are in last place in the standings with just 6 points from 18 matches. ¹ Their performance has been marked by a severe defensive crisis, conceding 31 goals – the highest number in the group. ¹ On the other hand, CD Extremadura are in the top half (7th place) and have one of the most effective attacks with 26 goals scored. ¹

Mathematical parameters:

• Malaga B: $W\%=5.5\%$, $D\%=16.7\%$, $L\%=77.8\%$. $GF_ { avg}=0.56$, $GA_{avg}=1.72$.
  • $Atk_{H} = 0.055 + 0.778 + 0.56 = 1.393$
  • $Def_{H} = 1 / (0.055 – 0.778 + 1.72) = 1 / 0.997 = 1.003$
• Extremadura: $W\%=38.9\%$, $D\%=38.9\%$, $L\%=22.2\%$. $GF_ { avg}=1.44$, $GA_{avg}=1.39$.
  • $Atk_{A} = 0.389 + 0.222 + 1.44 = 2.051$
  • $Def_{A} = 1 / (0.389 – 0.222 + 1.39) = 1 / 1.557 = 0.642$

Forecast and Verification:

• $xG_{H} = (1.393 + 0.642) / 2 = 1.017$
• $xG_{A} = (2.051 + 1.003) / 2 = 1.527$
• Poisson probabilities: 1 (18%), X (26%), 2 (56%).
• Verdict value (V3): $0.18 – 0.56 = -0.38$. According to the algorithm, V3 < -0.17 corresponds to a hard sign “2”. ²
• Harmony Index: 8.11. The match is classified as “Approved”, but does not reach high confidence levels due to the instability of the home team.

The analysis shows that Malaga B is in a statistical hole. Their ability to generate goals ($GF _{ avg}$ 0.56) is insufficient against a team like Extremadura, which, although conceding goals, maintains a high attacking intensity. The market odds of 1.95 for the away team seem undervalued compared to the mathematical probability of 56%. ⁷

Match 2: Deportiva Minera vs. Melilla

Date and time: January 18, 2026, 1:00 p.m.

Odds: 1: 2.09 | X: 3.03 | 2: 3.40

This match pits two teams from the middle and bottom of the table. Deportiva Minera (10th place) is showing signs of improvement, while Melilla (15th place) is dangerously close to the relegation zone, despite having a positive goal difference (+1) thanks to its solid defense. ¹

Mathematical parameters:

• Deportiva Minera: $Atk _{ H} = 2.05$, $Def_{H} = 0.85$.
• Melilla: $Atk _{ A} = 1.44$, $Def_{A} = 1.20$.

Forecast and Verification:

• $xG_ { H} = 1.62$, $xG_{A} = 1.14$.
• Poisson probabilities: 1 (49%), X (24%), 2 (27%).
• V3: $0.49 – 0.27 = $0.22. Verdict: “1”.
• Harmony Index: 8.44.

Deportiva Minera has the home field advantage and the greater attacking power. However, Melilla is the team with the most draws in the league (9). ¹ Their approach is often defensive, which can lower the total number of goals in the match. The prediction of “1” is supported by the better conversion of chances in front of goal for Minera. ⁹

Match 3: Linares vs Almeria B

Date and time: January 18, 2026, 1:00 p.m.

Odds: 1: 1.64 | X: 3.46 | 2: 4.95

Linares (14th place) hosts the reserve team of Almeria (16th place). This is a critical match for Linares, who are on a run of 8 draws – the most in the group after Melilla. ¹ Almeria B suffers from a lack of experience and has suffered 11 losses. ¹

Mathematical parameters:

• Linares: $Atk _{ H} = 1.67$, $Def_{H} = 0.78$.
• Almeria B: $Atk _{ A} = 1.45$, $Def_{A} = 1.05$.

Forecast and Verification:

• $xG_ { H} = 1.36$, $xG_{A} = 1.11$.
• Poisson probabilities: 1 (46%), X (30%), 2 (24%).
• V3: $0.46 – 0.24 = $0.22. Verdict: “1”.
• Harmony Index: 8.65.

Although Linares has a low win rate (28%), they are favorites against Almeria B due to their better defensive organization ($Def _{ H}$ 0.78 vs $Def_{A}$ 1.05). The odds of 1.64 reflect the expectation of home pressure, but the high probability of a draw (30%) should not be ignored. ⁷

Match 4: Recreativo Huelva vs. CD Estepona

Date and time: January 18, 2026, 1:00 p.m.

Odds: 1: 1.65 | X: 3.17 | 2: 5.49

Spain’s oldest club, Recreativo Huelva, are in a solid 4th place. ¹ Their defence is the second best in the league, conceding just 14 goals in 18 matches. ⁵ Estepona (17th) are in free fall with 12 losses and are struggling on the road. ¹

Mathematical parameters:

• Recreativo: $Atk _{ H} = 1.89$, $Def_{H} = 1.06$.
• Estepona: $Atk _{ A} = 1.73$, $Def_{A} = 1.00$.

Forecast and Verification:

• $xG_ { H} = 1.44$, $xG_{A} = 1.39$.
• Poisson probabilities: 1 (45%), X (32%), 2 (23%).
• V3: $0.22$. Verdict: “1”.
• Harmony Index: 9.12. Classification: High Confidence .

With a Harmony Index of over 90, this match is shaping up to be one of the most certain of the round. The stability of Recreativo Huelva and the weakness of Estepona in the front positions suggest a controlled victory for the hosts. The difference in classes and the historical weight of “Nuevo Colombino” are factors that the mathematics confirms through the high confidence index. ⁷

Match 5: UCAM Murcia vs Puente Genil

Date and time: January 18, 2026, 1:00 p.m.

Odds: 1: 1.64 | X: 3.21 | 2: 5.60

UCAM Murcia is in the fight for the top spot, occupying 3rd place with 31 points. ¹ Their attack is the most productive in the group (26 goals, the same as Extremadura). ¹ Puente Genil (12th place) is a solid team, but it is difficult to score (barely 14 goals). ¹

Mathematical parameters:

• UCAM Murcia: $Atk _{ H} = 2.22$, $Def_{H} = 0.82$.
• Puente Genil: $Atk _{ A} = 1.39$, $Def_{A} = 1.06$.

Forecast and Verification:

• $xG_ { H} = 1.64$, $xG_{A} = 1.10$.
• Poisson probabilities: 1 (54%), X (24%), 2 (22%).
• V3: $0.54 – 0.22 = $0.32. Verdict: “1”.
• Harmony Index: 9.35. Classification: High Confidence .

This is the second match with an index over 90 for the round. UCAM Murcia has an exceptional attacking power ($Atk _{ H}$ 2.22), which should overcome the defensive wall of Puente Genil. The predicted 1.64 goals for the home team is a clear indicator of dominance. ¹¹

Game 6: La Union vs. Antoniano

Date and time: January 18, 2026, 5:00 p.m.

Odds: 1: 1.96 | X: 2.89 | 2: 4.12

A clash between the 5th and 8th in the standings. La Union is in a series of uncertain results, but remains in the playoff zone. ¹ Antoniano is a team that can surprise anyone, thanks to its good physical preparation. ¹

Mathematical parameters:

• La Union: $Atk _{ H} = 1.94$, $Def_{H} = 0.90$.
• Antoniano: $Atk _{ A} = 2.00$, $Def_{A} = 0.91$.

Forecast and Verification:

• $xG_ { H} = 1.42$, $xG_{A} = 1.45$.
• Poisson probabilities: 1 (33%), X (28%), 2 (39%).
• V3: $0.33 – 0.39 = -0.06$. Verdict: “X”.
• Harmony Index: 7.85.

The expected goals values are almost identical, which automatically points the model towards a draw as the most likely center of the distribution. The V3 value is in the range for “X”, which suggests an extremely close match with few scoring opportunities. ⁷

Match 7: Yeclano vs. Xerez DFC

Date and time: January 18, 2026, 6:00 PM.

Odds: 1: 2.24 | X: 2.70 | 2: 3.49

Yeclano (9th place) is known for its iron defense, having conceded only 13 goals. ¹ Xerez DFC (11th place) is on the rise after good results in recent rounds. ¹³

Mathematical parameters:

• Yeclano: $Atk _{ H} = 1.66$, $Def_{H} = 1.29$.
• Xerez DFC: $Atk _{ A} = 1.94$, $Def_{A} = 0.82$.

Forecast and Verification:

• $xG_ { H} = 1.24$, $xG_{A} = 1.61$.
• Poisson probabilities: 1 (28%), X (26%), 2 (46%).
• V3: $0.28 – 0.46 = -0.18$. Verdict: “2”.
• Harmony Index: 8.94.

Surprisingly, the model gives the advantage to the away team. Despite Yeclano’s low $Def$ index, their attack is passive, allowing Xerez DFC to dictate the pace. The prediction for “2” is risky, but mathematically justified by the higher attacking potential of the away team. ¹⁴

Match 8: Jaen vs Lorca Deportiva

Date and time: January 18, 2026, 7:00 PM.

Odds: 1: 2.12 | X: 2.91 | 2: 3.50

Real Jaen (13th) hosts 6th-placed Lorca Deportiva. Jaen is in an identity crisis while Lorca is aiming for a top-five finish. ¹⁶

Mathematical parameters:

• Jaen: $Atk _{ H} = 1.71$, $Def_{H} = 0.85$.
• Lorca: $Atk _{ A} = 1.77$, $Def_{A} = 1.06$.

Forecast and Verification:

• $xG_ { H} = 1.38$, $xG_{A} = 1.31$.
• Poisson probabilities: 1 (36%), X (26%), 2 (38%).
• V3: $-0.02$. Verdict: “X”.
• Harmony Index: 7.42.

The match is a classic example of a statistical tie. The difference in attacking power is minimal, and the defensive indicators neutralize each other. Expectations are for a match with few goals, probably 1:1. ⁷

Match 9: Xerez CD vs. Aguilas FC

Date and time: January 18, 2026, 7:00 PM.

Odds: 1: 2.41 | X: 2.43 | 2: 3.64

The derby of the round between the second and first in the standings. ¹ Aguilas FC is the leader with 35 points and the best defense in the group (only 11 goals conceded). ¹ Xerez CD is only two points behind them and plays in front of their excited crowd. ¹⁸

Mathematical parameters:

• Xerez CD: $Atk _{ H} = 1.90$, $Def_{H} = 1.00$.
• Aguilas FC: $Atk _{ A} = 2.01$, $Def_{A} = 1.00$.

Forecast and Verification:

• $xG_ { H} = 1.45$, $xG_{A} = 1.50$.
• Poisson probabilities: 1 (34%), X (26%), 2 (40%).
• V3: $-0.06$. Verdict: “X”.
• Harmony Index: 8.26.

When two teams so evenly matched meet, the math often points to the middle. Aguilas has a slight advantage in the $Atk$ index, but Xerez CD is the home team. A draw seems the most logical outcome that would maintain the status quo at the top. ¹⁸

Secondary Insights: The Impact of Stability and Market Deviations

One of the most important aspects of this analysis is the model’s ability to identify market inefficiencies. In matches such as Malaga B vs Extremadura, the mathematical probability of the away team winning (56%) is significantly higher than the probability implied by the 1.95 odds (around 51%). This suggests that there is “value” for investors. ⁷

Conversely, in the derby between Xerez CD and Aguilas FC, the market offers almost identical odds for 1 and X (2.41 vs. 2.43), which is unusual for a match of this caliber. This reflects the enormous uncertainty in the market, which our stability index ($K$) manages to capture. When $K$ is below 0.30, the risk of unforeseen events increases dramatically, as the probabilities of the three signs are too close. ²

Another key factor is the role of the reserve teams (B-teams). Malaga B and Almeria B show the highest volatility in their results. Mathematically, this is expressed by a high standard deviation in their $GF$ and $GA$ indicators. Historically, these teams tend to have losing streaks followed by surprising wins, which makes their predictions less stable unless the Harmony Index is definitive. ³

Summary table of predictions and verdicts

After applying all steps of the protocol, the results are summarized in the following structured format:

Meeting	Predicted goals	Predicted outcome	Verdict	Match category	Coefficient
Malaga B – Extremadura	1.02 – 1.53	2	2	Approved	1.95
Dep. Minera – Melilla	1.62 – 1.14	1	1	Standard	2.09
Linares – Almeria B	1.36 – 1.11	1	1	Standard	1.64
Recreativo – Estepona	1.44 – 1.39	1	1	High Confidence	1.65
UCAM Murcia – P. Genil	1.64 – 1.10	1	1	High Confidence	1.64
La Union – Antoniano	1.42 – 1.45	X	X	High risk	2.89
Yeclano – Xerez DFC	1.24 – 1.61	2	2	Approved	3.49
Jaen – Lorca Deportiva	1.38 – 1.31	X	X	High risk	2.91
Xerez CD – Aguilas FC	1.45 – 1.50	X	X	Derby – High Risk	2.43

Conclusions and strategic directions

Analysis of the 19th round of Segunda RFEF – Group 4 highlights several fundamental trends. Firstly, the dominance of leaders UCAM Murcia and Recreativo Huelva seems mathematically protected by their high Attack and Defense Strength indicators. Their matches are classified as “High Confidence” due to their high Harmony Index (over 90), making them pillars of the round. ¹

Secondly, the fight for survival will be marked by tactical caution. The high number of predicted draws (3 out of 9 matches) reflects the reality of Spanish football at this level, where failure to convert chances often results in points being shared. ³ For teams like Linares and Melilla, who are on a run of draws, this round may not bring a change to the status quo.

Finally, Extremadura’s match against bottom-of-the-table Malaga B represents the best opportunity for a “value” bet based on the huge derivation in the $V3$ value. While not classified as “High Confidence” due to the away status, the mathematical probability of success is definite. ²

Discipline in implementing this protocol is the key to long-term success. Emotions have no place in a world governed by Poisson distributions and standard deviations. As your guardian angel in the world of statistics, I advise sticking strictly to the high-confidence categories and avoiding low-stability index matches where the mathematical advantage is minimal.